Nanomedicine: New Frontiers in Fighting Microbial Infections

Abstract

Microbes have dominated life on Earth for the past two billion years, despite facing a variety of obstacles. In the 20th century, antibiotics and immunizations brought about these changes. Since then, microorganisms have acquired resistance, and various infectious diseases have been able to avoid being treated with traditionally developed vaccines. Antibiotic resistance and pathogenicity have surpassed antibiotic discovery in terms of importance over the course of the past few decades. These shifts have resulted in tremendous economic and health repercussions across the board for all socioeconomic levels; thus, we require ground-breaking innovations to effectively manage microbial infections and to provide long-term solutions. The pharmaceutical and biotechnology sectors have been radically altered as a result of nanomedicine, and this trend is now spreading to the antibacterial research community. Here, we examine the role that nanomedicine plays in the prevention of microbial infections, including topics such as diagnosis, antimicrobial therapy, pharmaceutical administration, and immunizations, as well as the opportunities and challenges that lie ahead.

Full text

Citation: Mehrabi, M.R.; Soltani, M.;
Chiani, M.; Raahemifar, K.; Farhangi,
A. Nanomedicine: New Frontiers in
Fighting Microbial Infections.
Nanomaterials 2023,13, 483. https://
doi.org/10.3390/nano13030483
Academic Editor: Antonios Kelarakis
Received: 6 January 2023
Revised: 21 January 2023
Accepted: 22 January 2023
Published: 25 January 2023
Copyright: © 2023 by the authors.
Licensee MDPI, Basel, Switzerland.
This article is an open access article
distributed under the terms and
conditions of the Creative Commons
Attribution (CC BY) license (https://
creativecommons.org/licenses/by/
4.0/).
nanomaterials
Review
Nanomedicine: New Frontiers in Fighting Microbial Infections
Mohammad Reza Mehrabi 1, Madjid Soltani 2,3,4,5,* , Mohsen Chiani 1, Kaamran Raahemifar 6,7,8
and Ali Farhangi 1
1Department of NanoBiotechnology, Pasteur Institute of Iran, Tehran 13169-43551, Iran
2Department of Mechanical Engineering, K. N. Toosi University of Technology, Tehran 19967-15433, Iran
3Advanced Bioengineering Initiative Center, Multidisciplinary International Complex,
K. N. Toosi University of Technology, Tehran 14176-14411, Iran
4
Centre for Biotechnology and Bioengineering (CBB), University of Waterloo, Waterloo, ON N2L 3G1, Canada
5
Department of Electrical and Computer Engineering, University of Waterloo, Waterloo, ON N2L 3G1, Canada
6Data Science and Artificial Intelligence Program, College of Information Sciences and Technology (IST),
Penn State University, State College, PA 16801, USA
7Department of Chemical Engineering, University of Waterloo, 200 University Avenue West,
Waterloo, ON N2L 3G1, Canada
8School of Optometry and Vision Science, Faculty of Science, University of Waterloo,
200 University Avenue West, Waterloo, ON N2L 3G1, Canada
*Correspondence: msoltani@uwaterloo.ca
Abstract:
Microbes have dominated life on Earth for the past two billion years, despite facing a
variety of obstacles. In the 20th century, antibiotics and immunizations brought about these changes.
Since then, microorganisms have acquired resistance, and various infectious diseases have been able
to avoid being treated with traditionally developed vaccines. Antibiotic resistance and pathogenicity
have surpassed antibiotic discovery in terms of importance over the course of the past few decades.
These shifts have resulted in tremendous economic and health repercussions across the board for all
socioeconomic levels; thus, we require ground-breaking innovations to effectively manage microbial
infections and to provide long-term solutions. The pharmaceutical and biotechnology sectors have
been radically altered as a result of nanomedicine, and this trend is now spreading to the antibacterial
research community. Here, we examine the role that nanomedicine plays in the prevention of
microbial infections, including topics such as diagnosis, antimicrobial therapy, pharmaceutical
administration, and immunizations, as well as the opportunities and challenges that lie ahead.
Keywords: microbial infection; nanomedicine; vaccine; diagnosis; therapy
1. Introduction
Antibiotics and vaccines are among the greatest medical advances. Over the previous
century, broad-spectrum medicines and vaccinations greatly lowered infectious disease
morbidity and mortality [
1
–
3
]. Infectious disease mortality in the US declined dramatically
from 797 to 59 deaths per 100,000 between 1900 and 1996, with the lowest rate of 36 fatalities
per 100,000 in 1980. In recent decades, some worrying patterns have evolved that jeopardize
such progress. According to the World Health Organization’s Global Health Study from
2016, infectious and parasitic diseases are responsible for 9.7 percent of global deaths. The
top five causes of death worldwide are as follows: TB (2.3%), diarrheal bacterial infections
(2%), meningitis (0.5%), bacterial sexually transmitted disorders (syphilis, chlamydia, and
gonorrhea, 0.2%), and encephalitis (0.2%) [
4
]. The Global Burden of Diseases consortium
reports that Shigella and enterotoxigenic Escherichia coli are the most common and lethal
bacteria that cause infectious diarrhea [
5
,
6
]. In 2016, infectious diarrhea was the eighth
leading cause of death across all ages and the fifth leading cause of death among children.
Pneumococcus is the largest cause of years of disability across the globe, due to an increase
Nanomaterials 2023,13, 483. https://doi.org/10.3390/nano13030483 https://www.mdpi.com/journal/nanomaterials

Nanomaterials 2023,13, 483 2 of 27
of 2.82 million cases of meningitis in 2016 [
7
]. About 11 million people died from sepsis-
related causes in 2017 [
8
]. These numbers are significantly higher than the global average in
impoverished nations because of the lack of universal health systems, public health issues,
potable drinking water, and financial resources [
4
,
6
]. Antibiotic overuse has been linked to
its emergence. Antibiotic ineffectiveness that is caused by rising drug resistance is a major
threat to public health. Some researchers have even predicted that the 21st century will
be the “postantibiotic era” [
9
,
10
]. Multidrug resistance (MDR) is a phenomenon that can
occur in some bacteria [
11
]. Some multidrug-resistant infections are resistant to conven-
tional therapies. An alarming example of multidrug resistance is the increasing number
of strains of methicillin-resistant Staphylococcus aureus (MRSA) that are also resistant to
vancomycin (VRSA), complicating therapy because vancomycin is usually the last line of
defense against S. aureus infections [
12
]. Medication resistance, and new antimicrobial
drugs, are falling behind the rapid pace at which microbes evolve [
13
]. On the other hand,
traditional vaccinations that use live attenuated microorganisms, killed microbes, or micro-
bial components, have proven to be crucial to infectious disease control, although some do
not protect well. In addition, immunocompromised people should not utilize some live
vaccines. No vaccinations are available for many infectious illnesses. In order to overcome
these issues, a variety of vaccines that are based on isolated proteins, polysaccharides,
or naked DNA encoding a protective antigen, are being produced. Although these can
be safer, more defined, and less reactogenic than many vaccinations, they are often poor
immunogens that need adjuvants to improve their activity. The pharmaceutical industry
has slowed down the development of novel antibiotics, especially for MDR Gram-negative
superbugs, due to low returns on investment and R&D objectives [14,15].
The pharmaceutical and biotechnology industries have been revolutionized by nanome-
dicine, or the application of nanotechnologies in medicine [
16
–
22
]. Clinical use approval
has been granted for close to one hundred different nanomedicine products as of 2020.
These products range from medication delivery and imaging to implantable biomaterials
and medical devices [
18
]. Nanotechnologies can also tackle nearly every element of micro-
bial illness (Figure 1). Nanomaterials’ unique physicochemical properties have helped to
detect microbial diseases quickly, sensitively, and selectively. In addition, several inorganic
and organic nanoparticles have significant intrinsic antibacterial capabilities that are rarely
manifested in bulk form. More importantly, certain nanomaterials can reduce antibiotic re-
sistance by weakening the resistance pathways. In addition, nanoparticles for antimicrobial
drug delivery overcome resistance and have fewer adverse effects than the conventional
antibiotics. Medical equipment can also inhibit bacteria adherence and infection by using
antimicrobial nanoparticles. Last but not least, nanomaterials can boost immune responses
to microbial illness as vaccine adjuvants or delivery vehicles. For antigens that would
otherwise disintegrate quickly after injection, or cause a transient, the localized immune
response can be delivered in a more stable form via encapsulation in nanoparticles. The
possibility of integrating multiple antigens onto a single particle in order to protect against
more than one illness is also being investigated, as is the use of nanoparticles to deliver
vaccines by non-traditional routes, such as topical, inhalational, or optical delivery [
23
].
Here, we focus on the recent developments in nanotechnology that have been applied to
the fight against infectious microbes.

Nanomaterials 2023,13, 483 3 of 27
Nanomaterials 2023, 13, x FOR PEER REVIEW 3 of 28
Figure 1. Applications of nanomedicine in the treatment of infectious diseases caused by microbes.
Reproduced with permission from [24]. Copyright Elsevier, 2014.
2. Vaccination
It has been demonstrated that utilizing the host’s immune system to recognize and
kill germs protects the host against microbial infection. Pathogen-associated molecular
patterns help the innate immune system to identify pathogens that breach the host’s phys-
ical barriers [25]. Antigen-specific adaptive immune responses against bacterial infections
can persist for decades after activating antigen-presenting cells (APCs) [26]. The protec-
tive response may delay bacteremia and septic shock, giving antibiotics more time to
work. Microbe vaccines vary in immunogenicity and safety. Live attenuated bacterial vac-
cines raise concerns about pathogenicity reversion, vector immunity, and immune-com-
promised safety [27,28].
Isolated proteins, polysaccharides, and bare DNA are used to create next-generation
bacterial vaccines, thanks to biotechnology [29]. Compared to vaccinations that are made
from live, attenuated microbes, novel vaccines have a lower immune response. One pos-
sible answer lies in the use of nanotechnology to increase the effectiveness of vaccines on
the immune system. Nanoparticle antigens elicit systemic and local humoral immune re-
sponses, including IgG and IgA antibodies and cellular responses from Th1, Th2, and
Th17 cells [30]. Increased tissue penetration, access to the lymphatics, and preferential up-
take by APCs are just a few examples of how nanoparticles can stimulate the immune
system (Figure 2). Another way in which nanoparticles can do this includes the depot
effect, which stabilizes the antigens and controls their sustained release. The depot effect
involves the antigen and the adjuvant being displayed on the particle surface repeatedly
in order to stimulate B cell receptor co-aggregation, triggering, and activation. Nanopar-
ticle delivery technologies act as their adjuvants [30,31].
Figure 1.
Applications of nanomedicine in the treatment of infectious diseases caused by microbes.
Reproduced with permission from [24]. Copyright Elsevier, 2014.
2. Vaccination
It has been demonstrated that utilizing the host’s immune system to recognize and kill
germs protects the host against microbial infection. Pathogen-associated molecular patterns
help the innate immune system to identify pathogens that breach the host’s physical
barriers [
25
]. Antigen-specific adaptive immune responses against bacterial infections can
persist for decades after activating antigen-presenting cells (APCs) [
26
]. The protective
response may delay bacteremia and septic shock, giving antibiotics more time to work.
Microbe vaccines vary in immunogenicity and safety. Live attenuated bacterial vaccines
raise concerns about pathogenicity reversion, vector immunity, and immune-compromised
safety [27,28].
Isolated proteins, polysaccharides, and bare DNA are used to create next-generation
bacterial vaccines, thanks to biotechnology [
29
]. Compared to vaccinations that are made
from live, attenuated microbes, novel vaccines have a lower immune response. One
possible answer lies in the use of nanotechnology to increase the effectiveness of vaccines
on the immune system. Nanoparticle antigens elicit systemic and local humoral immune
responses, including IgG and IgA antibodies and cellular responses from Th1, Th2, and
Th17 cells [
30
]. Increased tissue penetration, access to the lymphatics, and preferential
uptake by APCs are just a few examples of how nanoparticles can stimulate the immune
system (Figure 2). Another way in which nanoparticles can do this includes the depot
effect, which stabilizes the antigens and controls their sustained release. The depot effect
involves the antigen and the adjuvant being displayed on the particle surface repeatedly in
order to stimulate B cell receptor co-aggregation, triggering, and activation. Nanoparticle
delivery technologies act as their adjuvants [30,31].
Nanoparticles deliver mucosal vaccinations well. Mucosal surfaces contain nearly 80% of
immunocytes and are the first line of defense [
32
]. A total of 70% of pathogens enter the body
through the mucosal surfaces [
33
]. Thus, a long-term mucosal immune response protects the
host from bacterial infection. Mucosal vaccination induces mucosal and systemic immunity,
while subcutaneous or intramuscular vaccines only induce a weak mucosal immune re-
sponse [
34
]. Thus, intranasal, inhalational, and gastrointestinal mucosal vaccinations are
becoming popular. Since the antigen must pass through several barriers before reaching the
APCs, mucosal immunization is limited. Mucosal vaccination could benefit from immunos-

Nanomaterials 2023,13, 483 4 of 27
timulatory nanoparticle delivery vehicles [
34
]. The main sites of mucosal immunological
activation are located in organized mucosa-associated lymphoid tissue (MALT), which can
be reached by these nanoparticles. Antigen-loaded nanoparticles that are engineered with
UEA-1 lectin, which selectively binds to M cells in MALT, have led to a two- to four-fold
rise in antibody titers [35].
Nanomaterials 2023, 13, x FOR PEER REVIEW 4 of 28
Figure 2. Immune response induction and how nanoparticles affect it [30]. Reproduced with per-
mission from [30]. Copyright Springer, Nature, 2013.
Nanoparticles deliver mucosal vaccinations well. Mucosal surfaces contain nearly
80% of immunocytes and are the first line of defense [32]. A total of 70% of pathogens
enter the body through the mucosal surfaces [33]. Thus, a long-term mucosal immune
response protects the host from bacterial infection. Mucosal vaccination induces mucosal
and systemic immunity, while subcutaneous or intramuscular vaccines only induce a
weak mucosal immune response [34]. Thus, intranasal, inhalational, and gastrointestinal
mucosal vaccinations are becoming popular. Since the antigen must pass through several
barriers before reaching the APCs, mucosal immunization is limited. Mucosal vaccination
could benefit from immunostimulatory nanoparticle delivery vehicles [34]. The main sites
of mucosal immunological activation are located in organized mucosa-associated lym-
phoid tissue (MALT), which can be reached by these nanoparticles. Antigen-loaded na-
noparticles that are engineered with UEA-1 lectin, which selectively binds to M cells in
MALT, have led to a two- to four-fold rise in antibody titers [35].
2.1. Adjuvant
Effective non-inflammatory mucosal adjuvants include nanoemulsions, which are
oil-in-water emulsions containing droplets on the nanoscale [36]. Potentially enhanced
antigen absorption, monocytes, and granulocyte recruitment, and cytokine and chemo-
kine release, may result from nanoemulsion adjuvanticity [30]. After one or two mucosal
injections, serum IgG and bronchial IgA and IgG antibodies were generated in mice and
guinea pigs by recombinant anthrax protective antigens that were combined in nanoemul-
sion [37]. The commercial human anthrax vaccine schedule consists of six subcutaneous
injections that are given at 18-month intervals, followed by annual booster shots. In order
to boost immunity against Burkholderia, scientists used nanoemulsion as a novel mucosal
Figure 2.
Immune response induction and how nanoparticles affect it [
30
]. Reproduced with
permission from [30]. Copyright Springer, Nature, 2013.
2.1. Adjuvant
Effective non-inflammatory mucosal adjuvants include nanoemulsions, which are oil-
in-water emulsions containing droplets on the nanoscale [
36
]. Potentially enhanced antigen
absorption, monocytes, and granulocyte recruitment, and cytokine and chemokine release,
may result from nanoemulsion adjuvanticity [
30
]. After one or two mucosal injections,
serum IgG and bronchial IgA and IgG antibodies were generated in mice and guinea pigs
by recombinant anthrax protective antigens that were combined in nanoemulsion [
37
].
The commercial human anthrax vaccine schedule consists of six subcutaneous injections
that are given at 18-month intervals, followed by annual booster shots. In order to boost
immunity against Burkholderia, scientists used nanoemulsion as a novel mucosal adjuvant
for the intranasal injection of Burkholderia multivorans outer membrane proteins antigen
in vaccinated mice. Neutralizing activity against Burkholderia was demonstrated by these
immune responses [38].
Cationic liposomes are used as an adjuvant in vaccinations. A cationic liposome-based
adjuvant called CAF01 has been proven to improve vaccine-candidate immune responses
and is currently in clinical testing [
39
]. In a study that was aimed at creating more effective
and safer tuberculosis vaccines, researchers found that combining CAF01 with a synthetic
mycobacterial glycolipid induced significant and protective Th1 and Th17 responses [
40
].

Nanomaterials 2023,13, 483 5 of 27
DC absorption and activation were prolonged by CAF01. The adjuvants for parenteral and
mucosal vaccines were cationic liposomes containing non-coding plasmid DNA. Mice of
the BALB/c strain were completely protected from a normally deadly lung challenge when
they were given a liposome–DNA complex as a mucosal adjuvant along with heat-killed
Burkholderia pseudomallei (B. pseudomallei) [41].
2.2. Vaccine Delivery
Small molecules, peptides, proteins, and nucleic acids can all be carried by polymeric
nanoparticles. Antigens and adjuvants can be transported through synthetic polymers,
which can then be injected into a patient [
42
]. An increase in CD4+ and CD8+ T cell subsets,
and Th1 antibody titers that were 64-fold higher than Th2, were observed after exposure to
PLGA nanoparticles expressing a recombinant major outer membrane protein of Chlamy-
dia trachomatis (C. trachomatis) [
43
]. Inactivated bacterial toxoid vaccinations have been
widely utilized to prevent and cure microbial illnesses by promoting antitoxin immunity.
Eliminating toxin virulence while maintaining antigenicity is still difficult. Zhang and
colleagues used erythrocyte membrane-coated polymeric nanoparticles to securely ad-
minister non-disrupted pore-forming toxins for immune processing (Figure 2) [
44
]. The
nanoparticle-detained toxin gave mice a greater protection against toxin-mediated deleteri-
ous effects, neutralized poisons, and 100% survival. Chitosan and pullulan have been used
to provide antigens against C. trachomatis and Streptococcus pneumonia [
45
,
46
]. Chitosan
promoted cytokine synthesis, making it an adjuvant. Chitosan-modified antigen-loaded
poly(e-caprolactone) nanoparticles increased IgG and IgA antibody responses [47].
In the case of protein oligomerization, self-assembling peptide nanoparticles (SAPNs)
take the form of icosahedral symmetric assemblies. These aggregates are called “virus-like
particles” (VLPs) due to their superficial similarity to viral capsids. SAPNs serve as a
framework that allows for the highly exposed presentation of inserted protein epitopes or
domains [
48
]. The introduction of different antigens into SAPNs can stimulate the production
of antibodies against low-immunogenic antigens. In the absence of an adjuvant, animals
that are immunized with SAPNs paired with an immunodominant B cell epitope that is
derived from the circumsporozoite protein of Plasmodium berghei developed high-affinity,
long-lasting T cell-dependent antibodies [49].
ISCOMs, or immune-stimulating complexes, are cage-like antigen delivery vehicles that
are composed of cholesterol, phospholipid, and saponin [
50
]. ISCOMs have the potential to
activate the IL-12-dependent components of the innate immune system and induce MHC class
I and class II antigen presentation. ISCOMs have also demonstrated effectiveness as mucosal
vaccines, especially when they are administered intranasally [
51
]. ISCOMs stimulate protec-
tive immune responses against Helicobacter pylori,Anaplasma marginale,Mycoplasma mycoides,
Mycobacterium tuberculosis,Corynebacterium diphtheriae,Streptococcus pyogenes,Moraxella Bovis,
and Chlamydia trachomatis [50].
3. Diagnosis
Contagious bacteria can spread infectious illnesses from sick people to healthy people.
Thus, rapid, sensitive, and specific pathogen detection is essential for detecting infection
sources, treating patients, and preventing illness [
52
,
53
]. Some of these illnesses are difficult
to diagnose due to the complexity and diversity of the microorganisms and the long
incubation period before the clinical symptoms arise (from minutes to years). ELISA and
PCR are sensitive and reproducible molecular methods for microbial infection detection.
However, these methods involve tedious sample preparation and extensive readout periods,
which may delay time-critical infection detection and treatment, such as bacterial sepsis.
These detection methods are also difficult to use in underdeveloped nations and rural parts
of industrialized countries, where microbial infectious illnesses are more common.
Nanotechnology can produce rapid, sensitive, specific, and cost-effective microbial
illness diagnosis methods [
54
]. Detecting target molecules/microbes in a complex sample
matrix requires selective capture and separation. Nanotechnology can aid both of these

Nanomaterials 2023,13, 483 6 of 27
processes, and nanoparticles’ unique physicochemical features may allow the recording
of a single binding event. Nanoparticles containing affinity probes, such as antibodies
and nucleic acids, can label or capture the targets by recognizing microbial biomarkers.
Nanoscale ligand arrays that target specific pathogens and surface patterning could also
significantly improve the detection of infectious diseases. Nanoparticles that are made of
magnetic materials, gold (Au), and fluorescent dyes are used in microbiological diagnosis.
3.1. Magnetic Nanoparticles
Superparamagnetic iron oxide nanoparticles (SPIONs) have been the subject of many
studies as contrast agents for magnetic resonance imaging (MRI) [
55
–
57
]. Research on the
use of magnetic nanoparticles that are coated with a probe in microbiological diagnostics
has also progressed significantly in recent years. Lowery and coworkers created a SPION
diagnostic technique based on T2-magnetic resonance (T2MR) that can detect five Candida
species in whole blood samples in a fast manner and with high reproducibility within three
hours [
58
]. The T2MR signal is significantly altered when oligonucleotide-decorated SPI-
ONs hybridize with amplified Candida DNA (Figure 3). Based on this method, T2Candida
is currently being utilized in clinical studies. Magneto-DNA nanoparticles were produced
by Weissleder and colleagues for clinical pathogen profiling [
24
]. These nanoparticles target
bacterial ribosomal RNA. Using a tiny nuclear magnetic resonance (NMR) device, the assay
was able to detect and phenotype 13 different bacterial species that were present in the
clinical specimens in under two hours.
Nanomaterials 2023, 13, x FOR PEER REVIEW 6 of 28
difficult to diagnose due to the complexity and diversity of the microorganisms and the
long incubation period before the clinical symptoms arise (from minutes to years). ELISA
and PCR are sensitive and reproducible molecular methods for microbial infection detec-
tion. However, these methods involve tedious sample preparation and extensive readout
periods, which may delay time-critical infection detection and treatment, such as bacterial
sepsis. These detection methods are also difficult to use in underdeveloped nations and
rural parts of industrialized countries, where microbial infectious illnesses are more com-
mon.
Nanotechnology can produce rapid, sensitive, specific, and cost-effective microbial
illness diagnosis methods [54]. Detecting target molecules/microbes in a complex sample
matrix requires selective capture and separation. Nanotechnology can aid both of these
processes, and nanoparticles’ unique physicochemical features may allow the recording
of a single binding event. Nanoparticles containing affinity probes, such as antibodies and
nucleic acids, can label or capture the targets by recognizing microbial biomarkers. Na-
noscale ligand arrays that target specific pathogens and surface patterning could also sig-
nificantly improve the detection of infectious diseases. Nanoparticles that are made of
magnetic materials, gold (Au), and fluorescent dyes are used in microbiological diagnosis.
3.1. Magnetic Nanoparticles
Superparamagnetic iron oxide nanoparticles (SPIONs) have been the subject of many
studies as contrast agents for magnetic resonance imaging (MRI) [55–57]. Research on the
use of magnetic nanoparticles that are coated with a probe in microbiological diagnostics
has also progressed significantly in recent years. Lowery and coworkers created a SPION
diagnostic technique based on T2-magnetic resonance (T2MR) that can detect five Can-
dida species in whole blood samples in a fast manner and with high reproducibility within
three hours [58]. The T2MR signal is significantly altered when oligonucleotide-decorated
SPIONs hybridize with amplified Candida DNA (Figure 3). Based on this method, T2Can-
dida is currently being utilized in clinical studies. Magneto-DNA nanoparticles were pro-
duced by Weissleder and colleagues for clinical pathogen profiling [24]. These nanoparti-
cles target bacterial ribosomal RNA. Using a tiny nuclear magnetic resonance (NMR) de-
vice, the assay was able to detect and phenotype 13 different bacterial species that were
present in the clinical specimens in under two hours.
Figure 3. (A) Candida T2MR assay process. (B) T2MR detecting particle reagent schematic. SPIONs
covalently conjugate oligonucleotide probes. Each target had two nanoparticle populations with a
target-complementary probe. These nanoparticles aggregate when hybridized to the target strand
Figure 3.
(
A
) Candida T2MR assay process. (
B
) T2MR detecting particle reagent schematic. SPIONs
covalently conjugate oligonucleotide probes. Each target had two nanoparticle populations with a
target-complementary probe. These nanoparticles aggregate when hybridized to the target strand
amplified in excess by asymmetric PCR, changing the sample’s T2MR signal. DNA concentration
increases clustering. Reproduced with permission from [59]. Copyright Elsevier, 2017.
Magnetic nanoparticles can be used to enrich, wash, and resuspend targets from a
complex biological matrix with the help of magnetic fields that can be controlled. It is
possible to identify bacteria in a sensitive and multiplex manner using this magnetic
nanoparticle profile and new detection technologies. Matrix-assisted laser desorption/mass
spectrometry, which is also known as MALDI-MS, is a technique that has been used to rapidly
and accurately identify bacteria [
60
]. This technique is based on the mass spectrometry
properties of common bacterial species. Rapid bacterial screening in clinical samples, such
as whole blood, is made possible through magnetic nanoparticle-based sample preparation
and concentration, as well as MALDI-MS detection [
60
,
61
]. In addition, ligand-modified

Nanomaterials 2023,13, 483 7 of 27
magnetic nanoparticles and magnetic microfluidic devices can eliminate pathogens and
endotoxins from the bloodstream [
62
,
63
]. When they are added to bovine whole blood,
magnetic nanoparticles that have been coated with the synthetic ligand bis-Zn-DPA have
the potential to eliminate E. coli with a clearance rate of around 100% at 60 mL/h.
In order to assess the metabolic activity and antibiotic resistance in bacteria, magnetic
nanoparticles were used to track nutrient consumption (e.g., starch). In order to determine
the susceptibility of bacteria in blood to antibiotics, Perez and colleagues [
63
] devised two
methods based on SPION that make use of magnetic relaxation. Low metabolic activity or
bacterial growth rates can trigger the assembly of Con A-conjugated SPIONs or dextran-
coated SPIONs supplied with free Con A, resulting in a shift in T2MR. After 2.5 h, or
5 min, depending on whether or not free Con A is present, ampicillin susceptibility can be
determined using a dextran-coated SPION competition assay. There is no need to incubate
the sample cells for 24 h using this method, yet it provides just as precise an assessment of
antibiotic sensitivity as the turbidity method.
3.2. Au Nanoparticles
Au nanoparticles’ unique optical and electrochemical characteristics, and their ability
to be surface-functionalized with probes, have made them popular sensing materials [
64
].
Since Mirkin and colleagues’ pioneering work [
65
], oligonucleotide-functionalized Au
nanoparticles have been frequently utilized as probes to quickly identify viruses whose
genome sequences include distinctive nucleic acid fingerprints. Oligonucleotide–Au
nanoparticles that are hybridized with target nucleic acids create a polymeric network and
move the plasmon resonance peak [
65
]. Storhoff and colleagues devised a “spot-and-read”
colorimetric approach for recognizing MRSA strains’ mecA genes using Au nanoparticles’
distance-dependent optical characteristics [
66
]. When they were spotted over an illumi-
nated glass waveguide, these nanoparticles hybridized and changed color, detecting the
nucleic acids with zeptomole sensitivity.
Au nanoparticle probes that are tagged with oligonucleotides and Raman-active dyes
can be used for the multiplexed detection of oligonucleotide targets with good sensitivity
and selectivity [
67
]. At 20 femtomolar concentrations, six distinct DNA targets were
distinguished by Au nanoparticle probes that were tagged with Raman rays. Using this
detection strategy, Mirkin and coworkers created a bio-barcode test for ultrasensitive nucleic
acid and protein targets [
68
]. For magnetic separation and dithiothreitol (DTT)-mediated
release of barcode strands, as shown in Figure 4, the targets of interest are sandwiched
between Au nanoparticles and magnetic microparticles. The Verigene test, which was
developed by Nanosphere, Inc., detects Gram-positive and Gram-negative bacteria directly
from blood samples using
in vitro
methods. After a positive blood culture, the results can
be delivered in 2–2.5 h with this test, compared to the normal 2–4 days with traditional
microbiological procedures. This test is two- to three-orders-of-magnitude more sensitive
than ELISA-based approaches [69].

Nanomaterials 2023,13, 483 8 of 27
Nanomaterials 2023, 13, x FOR PEER REVIEW 8 of 28
Figure 4. Assay using bio-barcodes for the detection of DNA and proteins. A representation in sche-
matic form of (a) the identification of proteins by the use of the bio-barcode test; (b) detection of
nucleic acids by the use of the bio-barcode test; as well as (c) the econometric detection method.
Reproduced with permission from [24]. Copyright Elsevier, 2014.
Affinity probes besides oligonucleotides have been described and demonstrated to
be useful for tagging Au nanoparticles for bacterial diagnosis. Gold nanoclusters that were
enclosed in lysozymes and designed to interact with peptidoglycans on bacterial cell walls
were produced to concentrate pathogenic germs for MALDIMS-based identification [70].
Stabilized gold nanoclusters against S. aureus and MRSA via human serum albumin or
its binding peptide motif were produced [71]. Gold nanoparticle antimicrobial resistance
can also be measured by monitoring the surface plasmon band shifts that are produced
by Con A-induced clustering of extra-coated Au nanoparticles in a bacterial solution with
starch [72].
3.3. Fluorescent Nanoparticles
Microbial detection has also been conducted with the use of nanomaterials or nano-
particles with fluorescent dyes. Antibody-conjugated silica nanoparticles containing hun-
dreds of fluorescent dye molecules for signal amplification were produced by Tan and
colleagues to allow for the in situ detection of single bacterial cells in less than twenty
minutes [73]. Multicolored FRET silica nanoparticles were created by co-encapsulating
three tandem dyes that emit various hues when they are excited with a single wavelength
[74]. Different monoclonal antibody-conjugated FRET silica nanoparticles detected vari-
ous bacterial targets simultaneously. Quantum dots (QDs), which are fluorescent semi-
conductor nanoparticles, have several advantages over traditional fluorophores, includ-
ing photobleaching resistance and size-tunable wide absorption spectra with narrow
emission [75]. QDs’ optical properties and variable surface chemistry make them a prom-
ising medium for complicated sample analysis and Listeria monocytogenes detection [76].
These affinity probes are promising for the high-throughput microbial identification of
biological and environmental samples due to their chemical and physical plasticity and
unique interactions with molecular targets or pathogens. Miniaturized devices with re-
duced sample quantities, quicker readouts, and improved sensitivity and accuracy will be
created. Most nanoparticle-based diagnostic techniques use targeted probes to recognize
known bacterial genome sequences/biomarkers and may not detect altered or novel bac-
teria strains. As drug-resistant strains grow, diagnostic nanotechnology that can detect
germs and determine their sensitivity to antimicrobials is another key avenue.
Figure 4.
Assay using bio-barcodes for the detection of DNA and proteins. A representation in
schematic form of (
a
) the identification of proteins by the use of the bio-barcode test; (
b
) detection
of nucleic acids by the use of the bio-barcode test; as well as (
c
) the econometric detection method.
Reproduced with permission from [24]. Copyright Elsevier, 2014.
Affinity probes besides oligonucleotides have been described and demonstrated to be
useful for tagging Au nanoparticles for bacterial diagnosis. Gold nanoclusters that were
enclosed in lysozymes and designed to interact with peptidoglycans on bacterial cell walls
were produced to concentrate pathogenic germs for MALDIMS-based identification [
70
].
Stabilized gold nanoclusters against S. aureus and MRSA via human serum albumin or
its binding peptide motif were produced [
71
]. Gold nanoparticle antimicrobial resistance
can also be measured by monitoring the surface plasmon band shifts that are produced
by Con A-induced clustering of extra-coated Au nanoparticles in a bacterial solution with
starch [72].
3.3. Fluorescent Nanoparticles
Microbial detection has also been conducted with the use of nanomaterials or nanopar-
ticles with fluorescent dyes. Antibody-conjugated silica nanoparticles containing hundreds
of fluorescent dye molecules for signal amplification were produced by Tan and colleagues
to allow for the in situ detection of single bacterial cells in less than twenty minutes [
73
].
Multicolored FRET silica nanoparticles were created by co-encapsulating three tandem dyes
that emit various hues when they are excited with a single wavelength [
74
]. Different mon-
oclonal antibody-conjugated FRET silica nanoparticles detected various bacterial targets
simultaneously. Quantum dots (QDs), which are fluorescent semiconductor nanoparticles,
have several advantages over traditional fluorophores, including photobleaching resistance
and size-tunable wide absorption spectra with narrow emission [
75
]. QDs’ optical proper-
ties and variable surface chemistry make them a promising medium for complicated sample
analysis and Listeria monocytogenes detection [
76
]. These affinity probes are promising for
the high-throughput microbial identification of biological and environmental samples due
to their chemical and physical plasticity and unique interactions with molecular targets or
pathogens. Miniaturized devices with reduced sample quantities, quicker readouts, and
improved sensitivity and accuracy will be created. Most nanoparticle-based diagnostic tech-
niques use targeted probes to recognize known bacterial genome sequences/biomarkers
and may not detect altered or novel bacteria strains. As drug-resistant strains grow, diagnos-
tic nanotechnology that can detect germs and determine their sensitivity to antimicrobials
is another key avenue.

Nanomaterials 2023,13, 483 9 of 27
4. Treatment
Antibiotic resistance is on the rise, posing a risk to the general population. Mutation
and horizontal gene transfer are two mechanisms by which bacteria acquire resistance [
77
].
Reduced drug uptake and drug efflux from the microbial cell, the increased synthesis of
a competitive inhibitor of antibiotics, and changes in the antibiotic-binding substrate are
the root causes of antimicrobial drug resistance [
78
]. Chronic infections that are induced
by biofilms and intracellular bacteria, including Mycobacterium leprae, Chlamydia, Lis-
teria, and others, are another major obstacle in antimicrobial therapy [
79
,
80
]. Biofilm is an
extracellular polymeric material (EPS) matrix that surrounds bacterial cells [
81
,
82
]. It traps
and degrades antibiotic compounds, preventing diffusion. Biofilm bacteria can withstand
various antibiotics 1000 times better than planktonic bacteria [
83
]. The host cell protects
the intracellular bacteria from several drugs. Chronic infections require frequent high-dose
antibiotics, therefore, their eradication is challenging.
Nanomedicine can cure microbial resistance without promoting it. Antimicrobial nano-
materials targeting numerous routes and the nanoparticle-based delivery of antibiotics might
achieve this. Antimicrobial nanotherapeutics that suppress biofilms and target intracellular
microorganisms may cure persistent infections. Nanomedicine is used to generate inor-
ganic and organic nanomaterials with intrinsic antibacterial characteristics (Figure 5A) and
nanoparticle-based antimicrobial medication delivery (Figure 5B).
Nanomaterials 2023, 13, x FOR PEER REVIEW 9 of 28
4. Treatment
Antibiotic resistance is on the rise, posing a risk to the general population. Mutation
and horizontal gene transfer are two mechanisms by which bacteria acquire resistance
[77]. Reduced drug uptake and drug efflux from the microbial cell, the increased synthesis
of a competitive inhibitor of antibiotics, and changes in the antibiotic-binding substrate
are the root causes of antimicrobial drug resistance [78]. Chronic infections that are in-
duced by biofilms and intracellular bacteria, including Mycobacterium leprae, Chla-
mydia, Listeria, and others, are another major obstacle in antimicrobial therapy [79,80].
Biofilm is an extracellular polymeric material (EPS) matrix that surrounds bacterial cells
[81,82]. It traps and degrades antibiotic compounds, preventing diffusion. Biofilm bacteria
can withstand various antibiotics 1000 times better than planktonic bacteria [83]. The host
cell protects the intracellular bacteria from several drugs. Chronic infections require fre-
quent high-dose antibiotics, therefore, their eradication is challenging.
Nanomedicine can cure microbial resistance without promoting it. Antimicrobial na-
nomaterials targeting numerous routes and the nanoparticle-based delivery of antibiotics
might achieve this. Antimicrobial nanotherapeutics that suppress biofilms and target in-
tracellular microorganisms may cure persistent infections. Nanomedicine is used to gen-
erate inorganic and organic nanomaterials with intrinsic antibacterial characteristics (Fig-
ure 5A) and nanoparticle-based antimicrobial medication delivery (Figure 5B).
Figure 5. Antimicrobial nanomaterials and nanoparticle-based drug delivery systems: a schematic
overview.
4.1. Antimicrobial Nanomaterials
4.1.1. Inorganic Nanoparticles
Metals and metal oxides: For centuries, metals and metal oxides have been used as
bactericidal agents in infection control [84–86]. Photocatalysis, photothermal effects, and
ROS-stimulating activities are unique to metal and metal oxide nanoparticles [87,88].
These nanoparticles’ huge surface-area-to-volume ratio allows easy surface functionaliza-
tion for more potent antibacterial agents.
Metal nanoparticles that are made of silver (Ag) have been studied the most exten-
sively. Several drug-resistant organisms, including Pseudomonas aeruginosa, ampicillin-
resistant Escherichia coli O157:H7, and erythromycin-resistant Streptococcus pyogenes,
may be susceptible to their toxicity [89]. The effects of Ag on bacteria and other microor-
ganisms are largely unknown. Ag compounds may be involved in bacterial cell death by
both direct and indirect interactions with membranes, DNA, enzymes, and proteins [87].
The transport of Ag+ ions, which are formed when Ag is exposed to ambient O2 and dis-
solved in water, is essential for Ag’s antibacterial effect. Since smaller Ag nanoparticles
Figure 5.
Antimicrobial nanomaterials and nanoparticle-based drug delivery systems: A schematic
overview.
4.1. Antimicrobial Nanomaterials
4.1.1. Inorganic Nanoparticles
Metals and metal oxides: For centuries, metals and metal oxides have been used as
bactericidal agents in infection control [
84
–
86
]. Photocatalysis, photothermal effects, and
ROS-stimulating activities are unique to metal and metal oxide nanoparticles [
87
,
88
]. These
nanoparticles’ huge surface-area-to-volume ratio allows easy surface functionalization for
more potent antibacterial agents.
Metal nanoparticles that are made of silver (Ag) have been studied the most extensively.
Several drug-resistant organisms, including Pseudomonas aeruginosa, ampicillin-resistant
Escherichia coli O157:H7, and erythromycin-resistant Streptococcus pyogenes, may be sus-
ceptible to their toxicity [
89
]. The effects of Ag on bacteria and other microorganisms are
largely unknown. Ag compounds may be involved in bacterial cell death by both direct
and indirect interactions with membranes, DNA, enzymes, and proteins [
87
]. The transport
of Ag+ ions, which are formed when Ag is exposed to ambient O2 and dissolved in water, is
essential for Ag’s antibacterial effect. Since smaller Ag nanoparticles have a higher surface-
area-to-volume ratio, their rate of Ag+ release and antibacterial activity are affected [
42
,
90
].
When compared to bulk Ag, Ag nanoparticles have significantly higher antibacterial activ-

Nanomaterials 2023,13, 483 10 of 27
ity. Their surface roughness, hydrophobicity, oxidation state, and functionalization also
impact Ag nanoparticles’ antibacterial activities [
91
]. For instance, glucosamine modifica-
tion of Ag nanoparticles’ surfaces improves their antibacterial effectiveness by entering
both Gram-negative and Gram-positive bacterial cells [92].
Tellurium (Te) and Bismuth (Bi) have also been researched for antibacterial therapy.
The nanoparticles outperformed Ag nanoparticles in antibacterial activity and lower tox-
icity [
93
]. ZnO, CuO, TiO
2
, Al
2
O
3
, and CeO
2
nanoparticles are also antibacterial [
94
].
For example, ZnO nanoparticles inhibit E. coli O157:H7 [
95
]. Metal oxide nanoparticles
suppress bacteria by the photocatalytic creation of ROS (which destroys their cellular
components), the reduction of bacterial membrane integrity, the disruption of energy trans-
duction and transport activities, and the reduction in respiratory enzyme activity and DNA
synthesis [96].
Metal and metal oxide nanoparticles as antimicrobials are hard for microorganisms to
resist. Metals/metal oxides have several mechanisms of action, making microorganism
resistance unlikely, unless multiple mutations occur concurrently. Ag, Bi, ZnO, and TiO
2
nanoparticles also inhibit biofilm [
97
]. Bi nanoparticles reduced Streptococcus mutant’s growth
by 69% and biofilm formation by 100% [
98
]. However, metal and metal oxide nanoparti-
cles are mostly used in medical devices to prevent bacterial adhesion and infection. Safety
concerns may limit their antimicrobial therapeutic use [
99
]. ZnO and TiO
2
damage DNA,
and CuO nanoparticles cause oxidative lesions [
99
]. Repeated injections accumulated Ag
nanoparticles in the liver, the lung, and the spleen, which could damage these organs [
100
].
These findings suggest that chronic exposure should be monitored for toxicity. Furthermore,
some metal and metal oxide nanomaterials may pose additional risks. Al
2
O
3
nanopar-
ticles promoted the horizontal conjugative transfer of MDR genes, increasing antibiotic
resistance [101].
Carbon: Although they are still under research, carbon-based nanomaterials, includ-
ing SWCNTs, MWCNTs, and fullerene, have been used in antibacterial applications [
102
].
These nanoparticles may kill bacteria through cell membrane disruption or photother-
mal/photodynamic characteristics [
103
]. Oxidative stress affects the bacterial membrane
integrity and metabolic activity, making SWCNTs effective against Gram-positive and
Gram-negative bacteria [
104
]. Fullerene has also been shown to be highly antibacterial.
Some investigations imply that the oxidative by-products from fullerene production may
cause toxicity [
105
]. Hydrophilic fullerene derivatives produce ROS efficiently and can be
employed as photosensitizers in antimicrobial photodynamic treatment (PDT). Antimicro-
bial PDT illuminates microbial pathogens and develops no innate resistance [106].
4.1.2. Peptide- and Polymer-based Nanoparticles
Cationic peptides: Cationic antimicrobial peptides (CAPs)—nature’s antibiotics—are
short amphipathic peptides that are found in all living forms, and they are effective against
many microorganisms, including MDR bacteria [
107
]. High-multicellular organisms’ mi-
crobial defense systems include CAPs [
108
]. CAPs harm negatively charged microbial
membranes, due to their cationic and hydrophobic characteristics. Cationic peptides’ cy-
totoxicity (e.g., hemolysis), enzymatic instability, and immunological surveillance restrict
the antibacterial use of hundreds of CAP sequences [
109
]. Thus, placing CAPs on sil-
ica or paramagnetic nanoparticles protects the peptides from proteolytic breakdown and
immunological recognition [110].
CAPs with cationic and amphipathic characteristics can self-assemble into nanos-
tructures that are less toxic and more effective against bacteria
in vivo
than unassembled
peptides [
111
]. Furthermore, nanostructure morphology has been linked to bioactivity,
suggesting that the nanostructure itself may contribute to antibacterial activity [
112
]. Yang
and colleagues created an amphiphilic peptide with cell-penetrating peptide TAT, six
arginine residues, and cholesterol that can self-assemble into core–shell nanoparticles
(Figure 6A,B) [
111
]. These nanoparticles can pass the blood–brain barrier and prevent
bacterial growth in S. aureus-infected rabbit brains. One recent study showed that hy-

Nanomaterials 2023,13, 483 11 of 27
droponically modified CAPs and rifampicin synergistically treated multi-drug resistant
and non-resistant TB and delayed rifampicin resistance [
113
]. Thus, CAP nanostructures
that encapsulate and distribute antibiotics may improve the therapeutic effectiveness of
combination therapies.
The advantages of the synthetic polymer analogs of CAPs include lower cost and
improved enzymatic stability [
114
]. Comparable antibacterial processes can be found in
quaternary ammonium and phosphonium polymers, which mimic CAPs. Figure 6C,D
show the self-assembly of micellar nanoparticles that are made from a CAP-mimicking,
amphiphilic triblock polymer. These nanoparticles suppress Gram-positive bacteria, MRSA,
and fungi by destroying their membranes, and they do so without causing hemolysis
at any dose. Even against Gram-negative E. coli and Gram-positive S. aureus, CAP-
mimicking poly[2-(tert-butylamino)ethyl methacrylate] nanofibers containing Ag nanopar-
ticles showed promising results [115].
Chitosan: Besides synthetic polymers, chitosan, which is a natural cationic polysaccha-
ride polymer, exhibits antibacterial properties. Polycationic chitosan, and its derivatives,
are antibacterial, due to their polycationic properties. The electrostatic contact increases
the microbial wall permeability, and chelating essential trace metals inhibits enzymes [
116
].
Due to its larger surface-area-to-volume ratio and microbe attraction, nanoscale chitosan
is a better antibacterial treatment than chitosan solution [
117
]. Chitosan nanoparticles
had a MIC of 0.25 g/mL against E. coli and S. aureus, compared to 20 g/mL for normal
chitosan molecules. Chitosan nanoparticles kill fungi and Gram-positive bacteria more
effectively than Gram-negative bacteria [
118
]. In addition, Friedman and colleagues found
that nanoparticles that are made of chitosan and alginate have direct bactericidal and
anti-inflammatory capabilities by reducing P. acnes-induced cytokine production [
119
].
These nanoparticles proved to be a promising topical dermatologic therapy when they
were encapsulated with benzoyl peroxide, which is an acne medication. Chitosan is hy-
drophilic and polycationic, making it a good carrier for antibiotics or a coating biomaterial
for stabilizing metallic nanoparticles [120].
Nanomaterials 2023, 13, x FOR PEER REVIEW 11 of 28
(Figure 6A,B) [111]. These nanoparticles can pass the blood–brain barrier and prevent bac-
terial growth in S. aureus-infected rabbit brains. One recent study showed that hydropon-
ically modified CAPs and rifampicin synergistically treated multi-drug resistant and non-
resistant TB and delayed rifampicin resistance [113]. Thus, CAP nanostructures that en-
capsulate and distribute antibiotics may improve the therapeutic effectiveness of combi-
nation therapies.
Figure 6. Images (A) and (B) are the chemical structure of the proposed peptide containing choles-
terol, glycine, arginine, and TAT, and represent the formation of micelles. Reproduced with permis-
sion from [121], American Chemical Society, 2013. Images (C) and (D) are the chemical structure of
cationic amphiphilic polycarbonate and represent the formation of micelles, as simulated by the
Materials Studio program utilizing molecular modeling. Reproduced with permission from [122].
Copyright American Chemical Society, 2015.
The advantages of the synthetic polymer analogs of CAPs include lower cost and
improved enzymatic stability [114]. Comparable antibacterial processes can be found in
quaternary ammonium and phosphonium polymers, which mimic CAPs. Figure 6C,D
show the self-assembly of micellar nanoparticles that are made from a CAP-mimicking,
amphiphilic triblock polymer. These nanoparticles suppress Gram-positive bacteria,
MRSA, and fungi by destroying their membranes, and they do so without causing hemol-
ysis at any dose. Even against Gram-negative E. coli and Gram-positive S. aureus, CAP-
mimicking poly [2-(tert-butylamino)ethyl methacrylate] nanofibers containing Ag nano-
particles showed promising results [115].
Chitosan: Besides synthetic polymers, chitosan, which is a natural cationic polysac-
charide polymer, exhibits antibacterial properties. Polycationic chitosan, and its deriva-
tives, are antibacterial, due to their polycationic properties. The electrostatic contact in-
creases the microbial wall permeability, and chelating essential trace metals inhibits en-
zymes [116]. Due to its larger surface-area-to-volume ratio and microbe attraction, na-
noscale chitosan is a better antibacterial treatment than chitosan solution [117]. Chitosan
nanoparticles had a MIC of 0.25 g/mL against E. coli and S. aureus, compared to 20 g/mL
for normal chitosan molecules. Chitosan nanoparticles kill fungi and Gram-positive bac-
teria more effectively than Gram-negative bacteria [118]. In addition, Friedman and col-
leagues found that nanoparticles that are made of chitosan and alginate have direct bac-
tericidal and anti-inflammatory capabilities by reducing P. acnes-induced cytokine pro-
duction [119]. These nanoparticles proved to be a promising topical dermatologic therapy
Figure 6.
Images (
A
) and (
B
) are the chemical structure of the proposed peptide containing cholesterol,
glycine, arginine, and TAT, and represent the formation of micelles. Reproduced with permission
from [
121
], American Chemical Society, 2013. Images (
C
) and (
D
) are the chemical structure of cationic
amphiphilic polycarbonate and represent the formation of micelles, as simulated by the Materials
Studio program utilizing molecular modeling. Reproduced with permission from [
122
]. Copyright
American Chemical Society, 2015.

Nanomaterials 2023,13, 483 12 of 27
4.2. Drug Delivery
Nanoparticles provide antibacterial agents, which is another important use. Nanoparticle-
based medication delivery might overcome antibiotic systemic toxicity, drug uptake and
efflux, biofilm development, and intracellular bacterial infection. Surface modification
with targeting ligands or microenvironment responsiveness can focus the nanoparticles
on the infection site, improving therapeutic efficacy and reducing antimicrobial medi-
cation adverse effects. The nanoparticle distribution of antimicrobial medications also
improves the hydrophobic drug solubility, the systemic circulation time, the drug half-life,
and the drug release, which may minimize systemic adverse effects and the administra-
tion frequency [
84
,
123
–
126
]. Liposomes, solid lipid nanoparticles, polymers, silica, and Au
nanoparticles have been produced to perform this [
84
,
127
]. Abelcet, AmBisome, Amphoteric,
and Fungisome are some of the liposomal/lipid complex antibiotic delivery technologies that
are licensed for human use.
Antibiotic resistance prevents microbial cells from attaining harmful drug concen-
trations through reduced uptake and enhanced efflux [
77
]. The outer membrane of Gram-
negative bacteria, such as P. aeruginosa and E. coli, may also reduce the uptake of hydrophobic
antibiotics, such as beta-lactams and macrolides [
128
]. An overexpression of transmembrane
pumps increases efflux and confers MDR on microorganisms, typically resulting in resistance
to chloramphenicol, fluoroquinolones, and macrolides [
128
]. Two recent reviews [
129
,
130
]
have found that some nanoparticle delivery vehicles weaken these resistance mechanisms.
Fusogenic liposomes that are made of specific lipids can fuse quickly with microbial plasma
membranes and deliver a high drug concentration into the cytoplasm, saturating the
transmembrane pumps [131].
Nanoparticle-based antibiotic delivery may help to fight biofilms and intracellular
bacteria, which cause persistent infections that are hard to treat with traditional antimicro-
bials. Liposomes and lipid-/polymer-based nanoparticles shield antibiotics from enzymes
and promote penetration, boosting their efficiency against biofilm-forming bacteria [
132
].
Liposome biofilm adherence might be increased by lipids such as phosphatidylinositol and
stearyl amine [
133
]. Nanoparticles infiltrate the host cells through endocytic/phagocytic
pathways and release their antibiotic payload into infection sites, due to their tiny size.
The mononuclear phagocyte system clears nanoparticles from the body and houses nu-
merous intracellular microorganisms [
134
]. Polyethylenimine-coated mesoporous silica
nanoparticles that were loaded with rifampin were more effective against Mycobacterium
tuberculosis-infected macrophages than free rifampin [
135
]. Nanoparticles for anti-biofilm
and intracellular infection therapy have been widely examined in recent reviews [136].
Conjugating several antibiotic copies on nanomaterial surfaces can boost antibac-
terial effectiveness because some antibiotics interact with bacterial surface components.
Au nanoparticles can attach antibiotic medicines to a solid surface and boost their antibacte-
rial activity by interacting with the cell walls [
137
]. The effectiveness of vancomycin-capped
Au nanoparticles in killing vancomycin-resistant Enterococcus and E. coli was increased by
a factor of 64 compared to vancomycin alone [
138
]. Several studies have shown that the an-
tibacterial activity of inert nanoparticles can be enhanced by the introduction of chemicals
that are either inactive as antibiotics or are less active than antibiotics. Amino-substituted
pyrimidine, which is inactive on its own, demonstrated a significant antibacterial effect
against MDR clinical isolates after being conjugated on a Au nanoparticle surface [139].
Nanoparticles also deliver nitric oxide (NO), which is a short-lived gaseous antibacte-
rial agent. NO inhibits DNA replication, cell respiration, and reactive nitrogen intermediate
production, which makes it antibacterial [
140
]. These pathways prevent bacterial resistance
to exogenous NO treatments [
141
]. Review publications [
142
,
143
] address several nanopar-
ticle platforms for NO delivery. For instance, silica nanoparticles that are produced with
NO donors (e.g., diazeniumdiolate) have outstanding antibacterial and biofilm-preventing
activity (>99.9%) against P. aeruginosa and E. coli [
144
]. When NO donors were encap-
sulated in biomaterials, such as PAMAM dendrimer and chitosan, these nanoparticles
had even greater bactericidal and anti-biofilm characteristics [
145
]. Besides encapsulating

Nanomaterials 2023,13, 483 13 of 27
NO-donating compounds, Friedman and colleagues created a sol–gel-based nanoparticle
system that can transport gaseous NO from the thermal reduction of nitrite and release it
in a regulated and sustained way [
146
]. NO nanoparticles inhibited several bacteria, even
drug-resistant ones. This solution holds NO in a stable state when it is dry and releases
gaseous NO when it is wet, making it promising for the topical treatment of wounds and
afflicted regions [
147
]. An MRSA-infected murine wound model showed rapid wound
healing and reduced bacterial burden [148].
A combination antibiotic treatment may prevent and treat drug resistance [
149
]. Addi-
tive or synergistic effects can boost medication potency and antibacterial activity. Resistance
to various drugs with diverse modes of action requires numerous gene changes in the
same bacterial cell, which is unlikely. Nanoparticles might deliver several antibiotics and
antimicrobial nanomaterials without synergistic/additive off-target effects. Rifampin and
azithromycin-loaded PLGA nanoparticles were more effective against chlamydial infec-
tions than either treatment alone [
150
]. Mesoporous silica that was loaded with peracetic
acid and Ag nanoparticles maintained their release and killed antibiotic-resistant and
biofilm-forming S. aureus [151].
Antimicrobial drugs could be more effective if they were delivered to the location of in-
fection via tailored nanoparticles rather than random ones. The treatment of slow-growing
or dormant bacterial infections, which are notoriously difficult to treat and require regular
high doses of antibiotics, may also benefit from this [
152
]. Ligand-modified nanoparticles
are used in conventional targeting because of their specificity for binding to receptors on the
surface of bacteria. Chlamydia infections, which upregulate folate receptor expression, were
treated with azithromycin and rifampicin that were given by PLGA nanoparticles that were
conjugated with folate. Liposomes containing ciprofloxacin that were mannose-conjugated
showed high selectivity for alveolar macrophages and successfully cured intracellular
respiratory tract infections [153].
A low pH, enzyme overexpression, localized bacterial toxins, and ligand-targeted
nanoparticle delivery are some of the other targeting strategies that have been used [
154
].
Antibiotic efficiency is reduced due to the local acidity that is caused by the bacterial
metabolism and the host immune response [
155
]. This process is the basis for the dis-
covery of pH-responsive, surface-charge-switching nanoparticles that mask non-specific
interactions at pH 7.4 but bind strongly to bacteria at pH 6.0 (Figure 7A,B). Vancomycin
that is enclosed in nanoparticles is superior to free drugs at an acidic pH. (Figure 7C).
Carboxyl-modified gold nanoparticles can be adsorbed to the exterior phospholipid layer
of liposomes, allowing for the liposomes to be turned off at a neutral pH and turned back
on at an acidic pH [
156
]. The combination of Au nanoparticles and liposomes in hydrogel
allows for sustained localized drug delivery [157].
The enzymes and toxins that are produced by bacteria can be employed for site-specific
applications. By incorporating themselves into the liposome membranes and releasing
the encapsulated therapeutic drugs, novel liposomes that were generated by Zhang and
colleagues can selectively deliver antibiotics to the areas of bacterial infection [
158
]. In
order to ensure that only bacteria-producing lipase is treated with vancomycin, Wang
and coworkers created a lipase-sensitive polymeric nanogel [
159
]. The drugs are released
from the polymeric nanogel when bacterially produced lipase breaks down the nanogel’s
polyphosphoester core and poly(e-caprolactone) barrier. The polymeric nanogel, which
has been coupled with macrophage-targeting ligands such as mannose, first attaches to
macrophages, then accumulates at the bacterial infection sites via macrophage-guided
transport, and finally releases the antibiotics upon contact with the lipase-secreting bacte-
ria [160].

Nanomaterials 2023,13, 483 14 of 27
Nanomaterials 2023, 13, x FOR PEER REVIEW 14 of 28
Figure 7. (A) Schematic of the nanoparticle-mediated drug targeting bacterial cell walls. A small
negative charge and surface PEGylation prevent nanoparticles from attaching to nontarget cells or
blood components at physiologic pH 7.4. The surface-charge-switching process activates at weakly
acidic infection sites, attaching nanoparticles to negatively charged bacteria. (B) PLGA—PLH—PEG
nanoparticles convert from anionic to cationic when the pH drops. (C) Minimum inhibitory concen-
trations (MIC) of S. aureus vancomycin formulation. * indicates p < 0.05. Reproduced with permis-
sion from [155]. Copyright American Chemical Society, 2012.
The enzymes and toxins that are produced by bacteria can be employed for site-spe-
cific applications. By incorporating themselves into the liposome membranes and releas-
ing the encapsulated therapeutic drugs, novel liposomes that were generated by Zhang
and colleagues can selectively deliver antibiotics to the areas of bacterial infection [158].
In order to ensure that only bacteria-producing lipase is treated with vancomycin, Wang
and coworkers created a lipase-sensitive polymeric nanogel [159]. The drugs are released
from the polymeric nanogel when bacterially produced lipase breaks down the nanogel’s
polyphosphoester core and poly(e-caprolactone) barrier. The polymeric nanogel, which
has been coupled with macrophage-targeting ligands such as mannose, first attaches to
macrophages, then accumulates at the bacterial infection sites via macrophage-guided
transport, and finally releases the antibiotics upon contact with the lipase-secreting bacte-
ria [160].
5. Preclinical and Clinical Translation
5.1. Preclinical Translation: Animal-tested Antimicrobial Nanoparticles
According to the type and the place of infection, nanoparticles that are compatible
with the biological environment should be used. In the following subsections, the studies
that have evaluated different nanoparticles against infections in animal models are dis-
cussed.
Figure 7.
(
A
) Schematic of the nanoparticle-mediated drug targeting bacterial cell walls. A small
negative charge and surface PEGylation prevent nanoparticles from attaching to nontarget cells or
blood components at physiologic pH 7.4. The surface-charge-switching process activates at weakly
acidic infection sites, attaching nanoparticles to negatively charged bacteria. (
B
) PLGA—PLH—
PEG nanoparticles convert from anionic to cationic when the pH drops. (
C
) Minimum inhibitory
concentrations (MIC) of S. aureus vancomycin formulation. * indicates p< 0.05. Reproduced with
permission from [155]. Copyright American Chemical Society, 2012.
5. Preclinical and Clinical Translation
5.1. Preclinical Translation: Animal-Tested Antimicrobial Nanoparticles
According to the type and the place of infection, nanoparticles that are compatible with
the biological environment should be used. In the following subsections, the studies that
have evaluated different nanoparticles against infections in animal models are discussed.
5.1.1. Skin and Subcutaneous Region Infection
Bacteria easily settle in skin lesions including atopic dermatitis and chronic wounds,
contributing to infection-induced inflammation and disease progression [
161
]. Due to the
obvious skin appearance, skin and subcutaneous infection are the best infection model
for animal-based research of nanomedicine’s antimicrobial effectiveness. Topical or subcu-
taneous bacterium injections establish this infection model easily. Topical, subcutaneous,
and intravenous nanoparticle distribution can treat cutaneous and subcutaneous infec-
tions. Au nanoparticles that were coated with chitosan and 2-mercapto-1-methylimidazole
(MMT) interacted multivalently with bacterial membranes [
162
]. A gelatin wound dress-
ing was made from nanoparticles and the nanoparticles were applied to a rabbit back
wound that was infected with MRSA. The nanocomposite-treated wound closed by 92%
after 16 days, while the gauze-treated wound closed by 67%. Liu et al. [
163
] developed
polydopamine-coated Au nanorods for subcutaneous infection chemo-photothermal treat-
ment. The polydopamine-coated nanorods loaded antibacterial Ag efficiently. Fluorescence
imaging showed that this platform became positively charged in the acidic abscess, allow-
ing bacteria to accumulate in the infection site. The loaded Ag released the pH sensitively.

Nanomaterials 2023,13, 483 15 of 27
Under near-infrared (NIR) irradiation, mice received this nanosystem intravenously in
order to cure a subcutaneous abscess. NIR hyperthermia increased Ag release and MRSA
killing for abscess ablation and wound healing.
Garlic contains antimicrobial allicin [
163
]. Sharifi-Rad et al. [
164
] treated MRSA-infected
mice with allicin and Ag nanoparticles. The allicin–Ag nanoparticle ointment inhibited the
skin MRSA infection synergistically. A photothermal nanocomposite of HA-templated
Ag nanoparticles combined with graphene oxide was created to treat skin S. aureus infec-
tion [
165
]. Bacterial hyaluronidase destroyed HA to liberate Ag. NIR light on graphene ox-
ide nanoparticles localized hyperthermia in order to kill the microorganisms. In the
in vivo
skin wound infection investigation, the nanoparticles with NIR had two orders fewer bacte-
ria than the control and NIR alone. Bacterial consortium and inflammation can result from
CVC exposure. Ribeiro et al. [
166
] immobilized Slavonian A-functionalized SPIONs on
CVC for antibacterial prophylaxis. CVC (40 mm) containing 20
µ
L of
1×109 CFU/mL K
.
of pneumonia caused mice to develop skin infections. A diode laser (808 nm) on the CVC
for five minutes reduced the bacterial survival by 88%. The antimicrobial activity lasted
for seven days. Cytokines lowered the inflammation. Acetylcysteine-coated Prussian blue
nanoparticles enabled photothermal treatment [
167
]. Mucolytic antibacterial acetylcysteine
and Prussian blue nanoparticles are NIR-triggered photothermal agents [
168
]. K4Fe(CN)6
and FeCl3 co-precipitated acetylcysteine-coated nanoparticles and NIR (980 nm) on the
nanoparticles at 50
µ
g/mL killed S. aureus and E. coli by 74% and 75%, respectively. Subcu-
taneous abscesses were cured by NIR exposure following nanocomposite injection.
Carvacrol was incorporated into poly(-caprolactone) (PCL) nanocarriers and combined
with hydrogel for topical distribution [
169
]. Monoterpene carvacrol kills several species
of bacteria [
170
]. Bacterial lipase released carvacrol from enzyme-sensitive nanoparticles.
Nanoparticle incorporation increased the carvacrol epidermal deposition from 0.04 to
0.96% of the administered dose in the dermatokinetic investigation. Carvacrol-loaded
hydrogel nanoparticles reduced the MRSA burden by 99.97% in pig skin burn wounds.
The hair follicles held 25% of the skin bacteria [
171
]. Eliminating hair follicle bacteria is
challenging. Hsu et al. [
172
] created chloramphenicol-loaded lipid-based nanocarriers for
follicular MRSA elimination. DMPC, or DA, was added to liposomes in order to create flexible
vesicles for easy extrusion into the follicles. Flexible liposomes containing DMPC and DA
increased intrafollicular drug uptake by 1.5- and 2-fold, respectively. Liposomes that were
used topically for seven days did not cause skin irritation. Lipid-based nanoparticles can also
be used to kill MRSA by combining SME and oxacillin in NLCs [
173
]. Cationic NLCs could
disrupt MRSA membranes and leak proteins. Oxacillin entered the cytoplasm after membrane
breakdown. Topical NLCs reduced the MRSA burden by four logs in mouse skin abscesses
and NLCs restored the skin architecture and the barrier function.
Yang et al. [
174
] created lipid bilayer-coated gentamicin-loaded MSNs. Ubiquicidin
adorned the MSN bilayer shells. Bacterial toxins could quickly release gentamicin from the
lipid bilayer. Planktonic and intra-macrophage S. aureus showed rapid antibiotic release.
Mice received intracellular S. aureus subcutaneously. After two days, the animals received
nanocomposite intravenously. After PBS and free-medication injections, the infected re-
gions had 2.3
×
107 and 8.4
×
106 CFU/mL, respectively. The nanoparticles reduced the
bacteria to 1.5
×
104 CFU/mL. The surfactants formed micelles. The antibacterial SMEs
were cationic surfactants that formed nanoscale micelles [
175
]. In the mouse model of sub-
cutaneous MRSA abscess, topically administered SME micelles reduced the bacterial load
by 1.6
×
104-fold compared to the vehicle control. Micelle’s intervention on healthy mouse
skin caused minimal cutaneous irritation, suggesting that it is a safe anti-MRSA therapy.
5.1.2. Pulmonary Infection
Pneumonia, TB, and cystic fibrosis are caused by respiratory tract bacteria. Nanofor-
mulations were administered intravenously or intratracheally to animals with lung infec-
tions. Tigecycline was the model antibiotic that was encapsulated in ICAM1-conjugated
β
-Ga2O3:Cr3+ nanoparticles by Kang et al. [
176
]. Inflammatory endothelial cells express

Nanomaterials 2023,13, 483 16 of 27
ICAM1. Bioimaging semiconductor
β
-Ga
2
O
3
:Cr
3+
is luminous [
177
]. In order to create
TRKP-infected pneumonia mice, intratracheal tigecycline-resistant K. pneumoniae (TRKP)
was injected into the lung. After 12 days, only the intravenous nanoparticle-treated animals
survived the pulmonary infection. The free-drug-treated mice at 45 mg/kg had an 83%
survival rate, which was lower than the nanocarrier-treated mice at 15 mg/kg. From 5 to
24 h post-injection, the nanoparticle-treated lung showed increased fluorescence intensity,
suggesting targeted administration boosted nanoparticle accumulation in the diseased area.
Polymer-based nanocarriers alleviate P. aeruginosa-induced lung infection. Inhaled
tobramycin cannot permeate DNA-rich lung mucus [
178
]. Deacon et al. [
179
] created
tobramycin-loaded chitosan/alginate nanoparticles with DNase to reduce mucus viscoelas-
ticity by DNA breakage. Pretreatment with biopolymer nanoparticles before lung infec-
tion with P. aeruginosa doubled the survival rate from 40% with free antibiotics to 80%.
DNase-containing nanoparticles penetrated the cystic fibrosis sputum more effectively.
Intratracheal PLGA nanoparticles carrying esculentin-1a cured lung infection in a study by
Casciaro et al. [
180
]. PVA stabilized the nanoparticles. The pulmonary mucus easily perme-
ated the neutral hydrophilic nanoparticles. Esculin-1a-loaded nanocarriers reduced CFU
by three logs in P. aeruginosa-infected mice. Free esculentin-1a had 17-fold less anti-P. aerug-
inosa action. Micelle nanocarriers were made by conjugating vancomycin with amphiphilic
PEG-co-PCL copolymer via pH-cleavable hydrazone linkages [
181
]. The nanocomposite
contained on-demand ciprofloxacin. Under acidic conditions, the nanocomposite’s van-
comycin shell opens, disrupting the hydrophilic/lipophilic balance and increasing the
micelle size, which helps the lipase that is overexpressed in the infection site to degrade
PCL and release ciprofloxacin to kill P. aeruginosa. The micelles reduced the lung bacterial
load and the alveolar damage in P. aeruginosa-infected mice.
A ROS-responsive 4-(hydroxymethyl) phenylboronic acid pinacol ester-modified
α
-
cyclodextrin was coated with phospholipids in order to generate lipid-coated nanoparticles
in order to deliver moxifloxacin to infected lung tissue and sustain drug release [
182
].
In the inflammatory zone, nanocarriers that were coated with 1,2-stearoyl-sn-glycerol-
3-phosphoethanolamine (DSPE)-PEG-folic acid allowed sputum to penetrate and target
macrophages with overexpressed ROS. Mice with lung P. aeruginosa infections received
the nanosystem intravenously. Moxifloxacin could increase the survival rate from 20%
to 40% following nanoparticulate encapsulation. Nanocomposite therapy eliminated the
lung pathogen colonies. PEGylated phosphatidylcholine-rich nanovesicles were tested for
infectious pneumonia treatment [
183
]. Ciprofloxacin-loaded nanovesicles targeted lung
surfactants. Intracellular MRSA may then disappear. After an intravenous injection of
lipid nanovesicles, lung ciprofloxacin accumulation increased 3.2-fold
in vivo
. The control
medication and nanovesicles reduced the pulmonary MRSA from 4.9
×
108 to 1.2
×
108
and 6.3 ×107 CFU, respectively.
Antimicrobial peptide NZX inhibits drug-resistant M. tuberculosis. Due to the macro-
phages’ high absorption of MSNs, Tenland et al. [
184
] tried to entrap NZX in them in order
to cure tuberculosis. Nanoparticles killed intra-macrophage bacteria more effectively than
free NZX. In the mouse tuberculosis model, intratracheal free peptide and NZX-containing
MSNs lowered lung M. tuberculosis CFU by 84% and 88%, respectively. MSNs also
actively targeted lung infections [
185
]. Vancomycin-loaded nanoparticles were coupled
with S. aureus-recognizing cyclic 9-amino-acid peptide CARGGLKSC (CARG). CARG
bound only to S. aureus
in vitro
. Intravenous CARG-conjugated nanoparticles had eight-
fold more lung deposition than non-targeted nanoparticles. S. aureus that was instilled
intratracheally into mouse lungs caused 67% mortality after 24 h. CARG-conjugated MSNs
enhanced the survival rate to 100%. All MSN-treated mice survived for 20 days.
5.1.3. Gastrointestinal (GI) Infection
Oral antimicrobial nanoparticles treat gastrointestinal infections. Nanocarriers pro-
tect antibiotics against GI fluid breakdown. Bioadhesive nanoparticles prolong GI tract
retention for oral bioavailability. Oral MSNs are suitable for GI medication enzymolysis pro-

Nanomaterials 2023,13, 483 17 of 27
tection. Zhao et al. [
186
] created intestine-targeted antimicrobial peptide defensin-loaded
MSNs. The stomach degrades defensin. Succinylated casein, which intestinal protease may
break down, was coated onto MSNs for intestinal targeting. In acidic conditions, casein
ornamentation lowered the defensin release, while trypsin controlled it. Orally gavaged
multidrug-resistant E. coli caused intestinal illness. Nanoparticles were taken orally daily
for five days. The casein-coated nanomedicine reduced the bacteria colonization more
than the free ciprofloxacin. Compared to the non-coated MSNs and the free peptides, the
casein-coated nanoparticles lowered the intestinal TNF-α1.5- and 2.2-fold.
Montmorillonite is a smectic clay with mucoadhesive and EPS-attaching proper-
ties [
187
]. H. pylori infection in GI patients was treated with a montmorillonite-cationic
PEI metronidazole nanocomposite [
188
]. By acting as a biomimetic building block, mont-
morillonite can zero in on bacteria, while PEI can facilitate bacterial membrane rupturing,
which improves the entry of antibiotics into the cytoplasm. Nanoparticles that are adminis-
tered orally showed widespread distribution in the stomach tissue, demonstrating their
mucoadhesion. Using nanocarriers to eliminate H. pylori in the gastrointestinal tract led
to a reduction in gastric ulcers and inflammation. Compared to omeprazole, amoxicillin,
and metronidazole, this triple therapy was more effective against germs. In order to create
biomimetic nanocarriers for targeting H. pylori, the gastric epithelial cell membrane was
coated onto PLGA nanoparticles [
189
]. H. pylori was attracted to the biomimetic nanocarri-
ers 10 times more than to the uncoated nanoparticles. After the oral administration of the
biomimetic nanoparticles and the free medicine, the bacterial burden in the stomachs of the
infected mice was reduced from 1.6 105 CFU/g to 6.5 103 and 5.0 104, respectively.
5.1.4. The Other Infection Sites
Antibacterial nanoparticles have been used to treat systemic, bone, and vaginal in-
fections. Systemic bacterial infections cause bacteremia and sepsis [
190
]. Rai et al. [
191
]
coupled high-density antibacterial peptides on Ag nanoparticles in order to eliminate
MRSA. This study used cecropin–melittin. Nanoparticles that are 14 nm might be regu-
lated. Bacteremia was treated in septic-like animals with intraperitoneal Au nanoparticles.
The circulation the MRSA concentration was two logs lower in the peptide-conjugated
nanoparticle group. The spleens received most of the nanoparticles. Metallic nanoparticles
were used to treat bone infections.
Ag–Cu nanoparticles by Qadri et al. [
192
] eliminated S. aureus bone infiltration in
mice. Boron was added to nanoparticles in order to prolong antibacterial action because its
anticorrosive properties delayed Cu oxidation [
193
]. The nanoparticles measured 27 nm.
S. aureus was inserted into the mice’s bones with a silk suture in order to cause osteomyelitis.
The 1 mg/kg intravenous nanoparticles reduced the bacterial CFU 10-fold compared to the
control. The S. aureus bone accumulation was also suppressed intramuscularly. Magnetic
Fe
3
O
4
nanoparticles and heat-disrupted biofilm were used to cure osteomyelitis [
194
]. The
S. aureus-infected bone received SPIONs. Infected bone magnetic fields were able to heat
the implant to 75
◦
C. Vancomycin in the femoral canal during heating killed the biofilm
microorganisms. Vancomycin and heat had 24% more bone volume than the infection
control (18%). ZnO nanoparticles showed a low-concentration of antibacterial activity [
195
].
A PVA hydrogel containing 10 nm ZnO nanoparticles treated vaginitis vaginally [
196
].
Vaginal E. coli inoculation for five days caused vaginitis in mice. The nanoparticles reduced
the CFU in vaginal washes. The histological epithelial exfoliation scores and the E. coli
counts were consistent.
5.2. Clinical Trials
The good news is that nanosystem-based antibiotics, antitoxin compounds, and an-
timicrobial peptides have been transferred to the clinic after substantial research into
revolutionary antimicrobial delivery systems to combat antibiotic resistance. Many are still
undergoing clinical testing (Table 1).

Nanomaterials 2023,13, 483 18 of 27
In a Phase 1 trial in healthy volunteers, Lipoquin was used to inhale ciprofloxacin-
loaded liposomes [
196
]. In 21 adult CF patients, a Phase 2a multi-center 14-day trial assessed
Lipoquin’s efficacy, early safety, and pharmacokinetics. In similar regions, ORBIT-3 and
ORBIT-4 were international, double-blind, randomized, Phase 3 trials of inhaled liposomal
ciprofloxacin’s safety and efficacy [
197
,
198
]. Amikacin-loaded liposomes were also studied
clinically. Individuals with a treatment-refractory nontuberculous mycobacteria lung
infection on a stable multidrug regimen were compared to a placebo over the course of
84 days in a double-blind, randomized study testing the efficacy, safety, and tolerability of
a once-daily amikacin 590 mg treatment [
199
]. For 18 months, patients with cystic fibrosis
who had chronic Pseudomonas aeruginosa infections in Phase 2 trial breathed in 560 mg of
amikacin-loaded liposomes once per day [
200
]. Liposomal amikacin (590 mg once per day
for 12 months), in combination with the current gold-standard mycobacterial multi-drug
regimen, for the treatment of mycobacterium abscesses in pulmonary illness will be tested
in a Phase 2 trial in order to determine its efficacy, safety, and tolerability [
201
]. Studying
the long-term safety and acceptability of inhaled amikacin-loaded liposome (590 mg/day)
in individuals with cystic fibrosis and persistent Pseudomonas aeruginosa infection will be
carried out in a Phase 3 clinical investigation [202].
Antibacterial drugs may benefit from a nano-preparation that targets bacterial toxins.
In 2016, the first human monoclonal antibody targeting Clostridium difficile toxin B was
approved, which was bezlotoxumab [
203
]. Monoclonal antibodies targeting S. aureus’
α
-
toxin and P. aeruginosa’s type III toxins secretory moiety are in clinical trials [
204
]. A broad-
spectrum antitoxin liposomal compound (CAL02) has synergistic effects with medicines or
antibiotics and can save mice from serious infections, such as staphylococci, by adsorbing
toxins [205].
Antimicrobial peptides have broad-spectrum antibacterial action and little resistance
risk due to their fast death [
206
]. Antimicrobial peptides target bacterial cell membranes.
Nisin, nucleic acid, RNA, protein, and statins are intracellular targets [206].
Table 1. Nanomaterial-based antimicrobials in different stages of the clinical trial.
Antimicrobial Trial Phase Application Ref.
Abelcet Marketed Fungal infection [207]
AmBisome Marketed Fungal infection [208]
Amphotec Marketed Fungal infection [209]
Fungisome Marketed Fungal infection [210]
Ciprofloxacin Phase 1 Pseudomonas aeruginosa [211]
Ciprofloxacin Phase 2a Pseudomonas aeruginosa [211]
Ciprofloxacin Phase 3 Bronchiectasis and Chronic P. Aeruginosa Infection [197]
Ciprofloxacin Phase 3 Non-cystic fibrosis bronchiectasis (NCFB) [212]
Amikacin Phase 2 Mycobacterium Infections, Nontuberculous [199]
Amikacin Phase 3 Cystic Fibrosis Patients with Chronic
Pseudomonas aeruginosa Infection [202]
Amikacin Phase 2 Mycobacterium Infections, Nontuberculous
Mycobacteria, Atypical [201]
Amikacin Phase 3 Mycobacterium Infections, Nontuberculous [213]
Amikacin Phase 2 Cystic Fibrosis [200]
Biological: CAL02 Phase 3 Severe community-acquired pneumonia [205]
Biological: GS-CDA1
Biological: MDX-1388 Phase 2 Clostridium Difficile Associated Disease [214]
Novacta biosystems (NVB-302) Phase 1 Clostridium difficile [215]
Human lactoferrin (hlf1-11) Phase 2 Infection following transplantation [216]
(a potent cyclic lipodepsipeptides
antibiotic) Wap-8294A2 Phase 2 Gm+ve bacteria (VRE and MRSA) [217]

Nanomaterials 2023,13, 483 19 of 27
Table 1. Cont.
Antimicrobial Trial Phase Application Ref.
The specifically targeted
antimicrobialpeptide (C16G2) Phase 2 Streptococcus mutans [218]
Antimicrobial Peptide (DPK-060) Phase 2 Acute external otitis [219]
LTX-109 (Lytixar) Phase 2 Nasal decolonization of MRSA Impetigo [220]
p2TA (AB 103) Phase 3 Necrotizing soft tissue infections [198]
Surotomycin Phase 3 Clostridium difficile [221]
Ramoplanin (NTI-851) Phase 2 Clostridium difficile [222]
6. Concluding Remarks
Nanotechnology is promising for microbial illness treatment. Due to its high adjustabil-
ity and broad range of adaptation, antibiotics with nanomaterials are a more cost-effective
option for macrophage persister cells and biofilm infections. Nano-antibiotic systems
can target, penetrate, absorb, and change infectious microenvironments, and combine
with other treatment techniques due to their nanomaterial design. Thus, nanomaterials
have considerable potential to improve antibiotic efficacy. Clinical translation must first
resolve various issues and testify carefully about
in vivo
toxicity and clinical effects. Nano-
antibiotics for resistant bacterial infections will require long-term research and practice
before their widespread use. Nanomaterials are still a promising antibiotic-resistance-
fighting option. We think that nano-antibiotics can combat bacterial resistance and save
more lives soon.
Funding: This research received no external funding.
Data Availability Statement: The study did not report any data.
Conflicts of Interest: The authors declare no conflict of interest.
References
1.
Armstrong, G.L.; Conn, L.A.; Pinner, R.W. Trends in Infectious Disease Mortality in the United States During the 20th Century.
JAMA 1999,281, 61–66. [CrossRef] [PubMed]
2. Cohen, M.L. Changing patterns of infectious disease. Nature 2000,406, 762–767. [CrossRef] [PubMed]
3.
Jadidi, A.; Salahinejad, E.; Sharifi, E.; Tayebi, L. Drug-delivery Ca-Mg silicate scaffolds encapsulated in PLGA. Int. J. Pharm.
2020
,
589, 119855. [CrossRef] [PubMed]
4.
World Health Organization (WHO). Global Health Estimates 2016: Disease Burden by Cause, Age, Sex, by Country and by
region, 2000–2016. 2018. Available online: https://www.who.int/healthinfo/global_burden_disease/estimates/en/index1.html
(accessed on 28 October 2020).
5.
Khalil, I.A.; Troeger, C.; Blacker, B.F.; Rao, P.C.; Brown, A.; Atherly, D.E.; Brewer, T.G.; Engmann, C.M.; Houpt, E.R.; Kang,
G. Morbidity and mortality due to shigella and enterotoxigenic Escherichia coli diarrhea: The Global Burden of Disease Study
1990–2016. Lancet Infect. Dis. 2018,18, 1229–1240. [CrossRef] [PubMed]
6.
GBD 2016 Diarrhoeal Disease Collaborators. Estimates of the global, regional, and national morbidity, mortality, and aetiologies
of diarrhoea in 195 countries: A systematic analysis for the Global Burden of Disease Study 2016. Lancet Infect. Dis.
2018
,18,
1211–1228. [CrossRef]
7.
Zunt, J.R.; Kassebaum, N.J.; Blake, N.; Glennie, L.; Wright, C.; Nichols, E.; Abd-Allah, F.; Abdela, J.; Abdelalim, A.; Adamu, A.A.
Global, regional, and national burden of meningitis, 1990–2016: A systematic analysis for the Global Burden of Disease Study
2016. Lancet Neurol. 2018,17, 1061–1082. [CrossRef]
8.
Rudd, K.E.; Johnson, S.C.; Agesa, K.M.; Shackelford, K.A.; Tsoi, D.; Kievlan, D.R.; Colombara, D.V.; Ikuta, K.S.; Kissoon, N.; Finfer,
S. Global, regional, and national sepsis incidence and mortality, 1990–2017: Analysis for the Global Burden of Disease Study.
Lancet 2020,395, 200–211. [CrossRef]
9. Kåhrström, C.T. Entering a post-antibiotic era? Nat. Rev. Genet. 2013,11, 146. [CrossRef]
10.
Lv, X.; Zhang, J.; Yang, D.; Shao, J.; Wang, W.; Zhang, Q.; Dong, X. Recent advances in pH-responsive nanomaterials for
anti-infective therapy. J. Mater. Chem. B 2020,8, 10700–10711. [CrossRef]
11. Alekshun, M.N.; Levy, S.B. Molecular Mechanisms of Antibacterial Multidrug Resistance. Cell 2007,128, 1037–1050. [CrossRef]
12.
Limbago, B.M.; Kallen, A.J.; Zhu, W.; Eggers, P.; McDougal, L.K.; Albrecht, V.S. Report of the 13th vancomycin-resistant
Staph-ylococcus aureus isolate from the United States. J. Clin. Microbiol. 2014,52, 998–1002. [CrossRef]

Nanomaterials 2023,13, 483 20 of 27
13.
Schäberle, T.F.; Hack, I.M. Overcoming the current deadlock in antibiotic research. Trends Microbiol.
2014
,22, 165–167. [CrossRef]
14. Taubes, G. The Bacteria Fight Back; American Association for the Advancement of Science: Washington, DC, USA, 2008.
15.
Boucher, H.W.; Talbot, G.H.; Benjamin, D.K., Jr.; Bradley, J.; Guidos, R.J.; Jones, R.N.; Murray, B.E.; Bonomo, R.A.; Gilbert, D. 10
×
‘20 Progress—Development of New Drugs Active Against Gram-Negative Bacilli: An Update from the Infectious Diseases Society
of America. Clin. Infect. Dis. 2013,56, 1685–1694. [CrossRef]
16.
Kashkooli, F.M.; Soltani, M.; Souri, M. Controlled anti-cancer drug release through advanced nano-drug delivery systems: Static
and dynamic targeting strategies. J. Control. Release 2020,327, 316–349. [CrossRef]
17.
Kashkooli, F.M.; Soltani, M.; Souri, M.; Meaney, C.; Kohandel, M. Nexus between in silico and
in vivo
models to enhance clinical
translation of nanomedicine. Nano Today 2021,36, 101057. [CrossRef]
18.
Souri, M.; Soltani, M.; Kashkooli, F.M.; Shahvandi, M.K.; Chiani, M.; Shariati, F.S.; Mehrabi, M.R.; Munn, L.L. Towards principled
design of cancer nanomedicine to accelerate clinical translation. Mater. Today Bio 2022,13, 100208. [CrossRef]
19.
Souri, M.; Soltani, M.; Kashkooli, F.M.; Shahvandi, M.K. Engineered strategies to enhance tumor penetration of drug-loaded
nanoparticles. J. Control. Release 2022,341, 227–246. [CrossRef]
20.
Soltani, M.; Kashkooli, F.M.; Souri, M.; Harofte, S.Z.; Harati, T.; Khadem, A.; Pour, M.H.; Raahemifar, K. Enhancing Clinical
Translation of Cancer Using Nanoinformatics. Cancers 2021,13, 2481. [CrossRef]
21.
Souri, M.; Chiani, M.; Farhangi, A.; Mehrabi, M.R.; Nourouzian, D.; Raahemifar, K.; Soltani, M. Anti-COVID-19 Nanomaterials:
Directions to Improve Prevention, Diagnosis, and Treatment. Nanomaterials 2022,12, 783. [CrossRef]
22.
Hu, Y.; Li, H.; Lv, X.; Xu, Y.; Xie, Y.; Yuwen, L.; Song, Y.; Li, S.; Shao, J.; Yang, D. Stimuli-responsive therapeutic systems for the
treatment of diabetic infected wounds. Nanoscale 2022,14, 12967–12983. [CrossRef]
23.
Gregory, A.E.; Titball, R.; Williamson, D. Vaccine delivery using nanoparticles. Front. Cell. Infect. Microbiol.
2013
,3, 13. [CrossRef]
[PubMed]
24.
Zhu, X.; Radovic-Moreno, A.F.; Wu, J.; Langer, R.; Shi, J. Nanomedicine in the management of microbial infection—Overview and
perspectives. Nano Today 2014,9, 478–498. [CrossRef] [PubMed]
25. Plotkin, S.A. Vaccines: Past, present and future. Nat. Med. 2005,11, S5–S11. [CrossRef]
26.
Choh, L.-C.; Ong, G.-H.; Vellasamy, K.M.; Kalaiselvam, K.; Kang, W.-T.; Al-Maleki, A.R.; Mariappan, V.; Vadivelu, J. Burkholderia
vaccines: Are we moving forward? Front. Cell. Infect. Microbiol. 2013,3, 5. [CrossRef] [PubMed]
27. Curtiss, R. Bacterial infectious disease control by vaccine development. J. Clin. Investig. 2002,110, 1061–1066. [CrossRef]
28.
Carleton, H.A. Combating Evolving Pathogens: Pathogenic Bacteria as Vaccine Vectors: Teaching Old Bugs New Tricks. Yale J.
Biol. Med. 2010,83, 217.
29.
Peek, L.J.; Middaugh, C.R.; Berkland, C. Nanotechnology in vaccine delivery. Adv. Drug Deliv. Rev.
2008
,60, 915–928. [CrossRef]
30.
Smith, D.M.; Simon, J.K.; Baker, J.R., Jr. Applications of nanotechnology for immunology. Nat. Rev. Immunol.
2013
,13, 592–605.
[CrossRef]
31.
Reddy, S.T.; van der Vlies, A.J.; Simeoni, E.; Angeli, V.; Randolph, G.J.; O’Neil, C.P.; Lee, L.K.; Swartz, M.A.; Hubbell, J.A.
Exploiting lymphatic transport and complement activation in nanoparticle vaccines. Nat. Biotechnol.
2007
,25, 1159–1164.
[CrossRef]
32. Holmgren, J.; Czerkinsky, C. Mucosal immunity and vaccines. Nat. Med. 2005,11, S45–S53. [CrossRef]
33.
Neutra, M.R.; Pringault, E.; Kraehenbuhl, J.-P. Antigen Sampling Across Epithelial Barriers and Induction of Mucosal Immune
Responses. Annu. Rev. Immunol. 1996,14, 275–300. [CrossRef]
34.
Kammona, O.; Kiparissides, C. Recent advances in nanocarrier-based mucosal delivery of biomolecules. J. Control. Release
2012
,
161, 781–794. [CrossRef]
35.
Manocha, M.; Pal, P.C.; Chitralekha, K.; Thomas, B.E.; Tripathi, V.; Gupta, S.D.; Paranjape, R.; Kulkarni, S.; Rao, D.N. Enhanced
mucosal and systemic immune response with intranasal immunization of mice with HIV peptides entrapped in PLG mi-
croparticles in combination with Ulex europaeus-I lectin as M cell target. Vaccine 2005,23, 5599–5617. [CrossRef] [PubMed]
36.
Hamouda, T.; Myc, A.; Donovan, B.; Shih, A.Y.; Reuter, J.D.; Baker, J.R. A novel surfactant nanoemulsion with a unique non-irritant
topical antimicrobial activity against bacteria, enveloped viruses and fungi. Microbiol. Res. 2001,156, 1–7. [CrossRef]
37.
Bielinska, A.U.; Janczak, K.W.; Landers, J.J.; Makidon, P.; Sower, L.E.; Peterson, J.W.; Baker, J.R., Jr. Mucosal immunization with a
novel nanoemulsion-based recombinant anthrax protective antigen vaccine protects against Bacillus anthracis spore chal-lenge.
Infect. Immun. 2007,75, 4020–4029. [CrossRef]
38.
Makidon, P.E.; Knowlton, J.; Groom, J.V.; Blanco, L.P.; Lipuma, J.J.; Bielinska, A.U.; Baker, J.R. Induction of immune response to
the 17 kDa OMPA Burkholderia cenocepacia polypeptide and protection against pulmonary infection in mice after nasal vaccination
with an OMP nanoemulsion-based vaccine. Med. Microbiol. Immunol. 2010,199, 81–92. [CrossRef]
39.
Martel, C.J.-M.; Agger, E.M.; Poulsen, J.J.; Jensen, T.H.; Andresen, L.; Christensen, D.; Nielsen, L.P.; Blixenkrone-Møller, M.;
Andersen, P.; Aasted, B. CAF01 Potentiates Immune Responses and Efficacy of an Inactivated Influenza Vaccine in Ferrets. PLoS
ONE 2011,6, e22891. [CrossRef]
40.
Kamath, A.T.; Rochat, A.-F.; Christensen, D.; Agger, E.M.; Andersen, P.; Lambert, P.-H.; Siegrist, C.-A. A liposome-based my-
cobacterial vaccine induces potent adult and neonatal multifunctional T cells through the exquisite targeting of dendritic cells.
PLoS ONE 2009,4, e5771. [CrossRef]
41.
Henderson, A.; Propst, K.; Kedl, R.; Dow, S. Mucosal immunization with liposome-nucleic acid adjuvants generates effective
humoral and cellular immunity. Vaccine 2011,29, 5304–5312. [CrossRef] [PubMed]

Nanomaterials 2023,13, 483 21 of 27
42.
Blecher, K.; Nasir, A.; Friedman, A. The growing role of nanotechnology in combating infectious disease. Virulence
2011
,2,
395–401. [CrossRef]
43.
Fairley, S.J.; Singh, S.R.; Yilma, A.N.; Waffo, A.B.; Subbarayan, P.; Dixit, S.; Taha, M.A.; Cambridge, C.D.; Dennis, V.A. Chlamydia
trachomatis recombinant MOMP encapsulated in PLGA nanoparticles triggers primarily T helper 1 cellular and antibody immune
responses in mice: A desirable candidate nanovaccine. Int. J. Nanomed. 2013,8, 2085–2099. [CrossRef]
44.
Hu, C.-M.J.; Fang, R.H.; Luk, B.T.; Zhang, L. Nanoparticle-detained toxins for safe and effective vaccination. Nat. Nanotechnol.
2013,8, 933–938. [CrossRef]
45.
Kong, I.G.; Sato, A.; Yuki, Y.; Nochi, T.; Takahashi, H.; Sawada, S.; Mejima, M.; Kurokawa, S.; Okada, K.; Sato, S.; et al. Nanogel-
Based PspA Intranasal Vaccine Prevents Invasive Disease and Nasal Colonization by Streptococcus pneumoniae. Infect. Immun.
2013,81, 1625–1634. [CrossRef] [PubMed]
46.
Cambridge, C.D.; Singh, S.R.; Waffo, A.B.; Fairley, S.J.; Dennis, V.A. Formulation, characterization, and expression of a re-
combinant MOMP Chlamydia trachomatis DNA vaccine encapsulated in chitosan nanoparticles. Int. J. Nanomed.
2013
,8,
1759–1771.
47.
Florindo, H.; Pandit, S.; Lacerda, L.; Gonçalves, L.; Alpar, H.; Almeida, A. The enhancement of the immune response against S.
equi antigens through the intranasal administration of poly-
E
-caprolactone-based nanoparticles. Biomaterials
2009
,30, 879–891.
[CrossRef]
48.
Schroeder, U.; Graff, A.; Buchmeier, S.; Rigler, P.; Silvan, U.; Tropel, D.; Jockusch, B.M.; Aebi, U.; Burkhard, P.; Schoenenberger,
C.-A. Peptide Nanoparticles Serve as a Powerful Platform for the Immunogenic Display of Poorly Antigenic Actin Determinants.
J. Mol. Biol. 2009,386, 1368–1381. [CrossRef]
49.
Kaba, S.A.; Brando, C.; Guo, Q.; Mittelholzer, C.; Raman, S.; Tropel, D.; Aebi, U.; Burkhard, P.; Lanar, D.E. A nonadjuvanted
pol-ypeptide nanoparticle vaccine confers long-lasting protection against rodent malaria. J. Immunol.
2009
,183, 7268–7277.
[CrossRef]
50. Sun, H.-X.; Xie, Y.; Ye, Y.-P. ISCOMs and ISCOMATRIX™. Vaccine 2009,27, 4388–4401. [CrossRef]
51.
Hu, K.-F.; Lövgren-Bengtsson, K.; Morein, B. Immunostimulating complexes (ISCOMs) for nasal vaccination. Adv. Drug Deliv.
Rev. 2001,51, 149–159. [CrossRef]
52. Salyers, A.A.; Whitt, D.D.; Whitt, D.D. Bacterial Pathogenesis: A Molecular Approach; ASM Press: Washington, DC, USA, 1994.
53.
Allegranzi, B.; Nejad, S.B.; Combescure, C.; Graafmans, W.; Attar, H.; Donaldson, L.; Pittet, D. Burden of endemic health-care-
associated infection in developing countries: Systematic review and meta-analysis. Lancet 2011,377, 228–241. [CrossRef]
54.
Kaittanis, C.; Santra, S.; Perez, J.M. Emerging nanotechnology-based strategies for the identification of microbial pathogenesis.
Adv. Drug Deliv. Rev. 2010,62, 408–423. [CrossRef]
55.
Xie, J.; Liu, G.; Eden, H.S.; Ai, H.; Chen, X. Surface-Engineered Magnetic Nanoparticle Platforms for Cancer Imaging and Therapy.
Acc. Chem. Res. 2011,44, 883–892. [CrossRef]
56.
Souri, M.; Kashkooli, F.M.; Soltani, M. Analysis of Magneto-Hyperthermia Duration in Nano-sized Drug Delivery System to
Solid Tumors Using Intravascular-Triggered Thermosensitive-Liposome. Pharm. Res. 2022,39, 753–765. [CrossRef]
57.
Souri, M.; Soltani, M.; Kashkooli, F.M. Computational modeling of thermal combination therapies by magneto-ultrasonic heating
to enhance drug delivery to solid tumors. Sci. Rep. 2021,11, 19539. [CrossRef]
58. Chow, E.K.-H.; Ho, D. Cancer Nanomedicine: From Drug Delivery to Imaging. Sci. Transl. Med. 2013,5, 216rv4. [CrossRef]
59.
Neely, L.A.; Audeh, M.; Phung, N.A.; Min, M.; Suchocki, A.; Plourde, D.; Blanco, M.; Demas, V.; Skewis, L.R.; Anagnostou, T.;
et al. T2 Magnetic Resonance Enables Nanoparticle-Mediated Rapid Detection of Candidemia in Whole Blood. Sci. Transl. Med.
2013,5, 182ra54. [CrossRef]
60.
Bizzini, A.; Durussel, C.; Bille, J.; Greub, G.; Prod’Hom, G. Performance of Matrix-Assisted Laser Desorption Ionization-Time of
Flight Mass Spectrometry for Identification of Bacterial Strains Routinely Isolated in a Clinical Microbiology Laboratory. J. Clin.
Microbiol. 2010,48, 1549–1554. [CrossRef]
61.
Lin, Y.-S.; Tsai, P.-J.; Weng, M.-F.; Chen, Y.-C. Affinity Capture Using Vancomycin-Bound Magnetic Nanoparticles for the
MALDI-MS Analysis of Bacteria. Anal. Chem. 2005,77, 1753–1760. [CrossRef]
62.
Lee, J.-J.; Jeong, K.J.; Hashimoto, M.; Kwon, A.H.; Rwei, A.; Shankarappa, S.A.; Tsui, J.H.; Kohane, D.S. Synthetic Ligand-Coated
Magnetic Nanoparticles for Microfluidic Bacterial Separation from Blood. Nano Lett. 2014,14, 1–5. [CrossRef]
63.
Kaittanis, C.; Nath, S.; Perez, J.M. Rapid Nanoparticle-Mediated Monitoring of Bacterial Metabolic Activity and Assessment of
Antimicrobial Susceptibility in Blood with Magnetic Relaxation. PLoS ONE 2008,3, e3253. [CrossRef]
64.
Uehara, N. Polymer-functionalized Gold Nanoparticles as Versatile Sensing Materials. Anal. Sci.
2010
,26, 1219–1228. [CrossRef]
[PubMed]
65.
Elghanian, R.; Storhoff, J.J.; Mucic, R.C.; Letsinger, R.L.; Mirkin, C.A. Selective Colorimetric Detection of Polynucleotides Based
on the Distance-Dependent Optical Properties of Gold Nanoparticles. Science 1997,277, 1078–1081. [CrossRef]
66.
Storhoff, J.J.; Lucas, A.D.; Garimella, V.; Bao, Y.P.; Müller, U.R. Homogeneous detection of unamplified genomic DNA sequences
based on colorimetric scatter of gold nanoparticle probes. Nat. Biotechnol. 2004,22, 883–887. [CrossRef] [PubMed]
67.
Cao, Y.C.; Jin, R.; Mirkin, C.A. Nanoparticles with Raman Spectroscopic Fingerprints for DNA and RNA Detection. Science
2002
,
297, 1536–1540. [CrossRef] [PubMed]
68.
Hill, H.D.; Mirkin, C.A. The bio-barcode assay for the detection of protein and nucleic acid targets using DTT-induced ligand
exchange. Nat. Protoc. 2006,1, 324–336. [CrossRef]

Nanomaterials 2023,13, 483 22 of 27
69. Scott, L.J. Verigene®Gram-Positive Blood Culture Nucleic Acid Test. Mol. Diagn. Ther. 2013,17, 117–122. [CrossRef]
70.
Chan, P.-H.; Wong, S.-Y.; Lin, S.-H.; Chen, Y.-C. Lysozyme-encapsulated gold nanocluster-based affinity mass spectrometry for
pathogenic bacteria. Rapid Commun. Mass Spectrom. 2013,27, 2143–2148. [CrossRef]
71.
Chan, P.-H.; Chen, Y.-C. Human serum albumin stabilized gold nanoclusters as selective luminescent probes for Staphylo-coccus
aureus and methicillin-resistant Staphylococcus aureus.Anal. Chem. 2012,84, 8952–8956. [CrossRef]
72.
Nath, S.; Kaittanis, C.; Tinkham, A.; Perez, J.M. Dextran-coated gold nanoparticles for the assessment of antimicrobial suscep-
tibility. Anal. Chem. 2008,80, 1033–1038. [CrossRef]
73.
Zhao, X.; Hilliard, L.R.; Mechery, S.J.; Wang, Y.; Bagwe, R.P.; Jin, S.; Tan, W. A rapid bioassay for single bacterial cell quantitation
using bioconjugated nanoparticles. Proc. Natl. Acad. Sci. USA 2004,101, 15027–15032. [CrossRef]
74.
Wang, L.; Zhao, W.; O’Donoghu, M.B.; Tan, W. Fluorescent Nanoparticles for Multiplexed Bacteria Monitoring. Bioconjugate Chem.
2007,18, 297–301. [CrossRef]
75.
Zrazhevskiy, P.; Sena, M.; Gao, X. Designing multifunctional quantum dots for bioimaging, detection, and drug delivery. Chem.
Soc. Rev. 2010,39, 4326–4354. [CrossRef]
76.
Tully, E.; Hearty, S.; Leonard, P.; O’Kennedy, R. The development of rapid fluorescence-based immunoassays, using quantum
dot-labelled antibodies for the detection of Listeria monocytogenes cell surface proteins. Int. J. Biol. Macromol.
2006
,39, 127–134.
[CrossRef]
77. Jayaraman, R. Antibiotic resistance: An overview of mechanisms and a paradigm shift. Curr. Sci. 2009,96, 1475–1484.
78.
Pelgrift, R.Y.; Friedman, A.J. Nanotechnology as a therapeutic tool to combat microbial resistance. Adv. Drug Deliv. Rev.
2013
,65,
1803–1815. [CrossRef]
79.
Ray, K.; Marteyn, B.; Sansonetti, P.J.; Tang, C.M. Life on the inside: The intracellular lifestyle of cytosolic bacteria. Nat. Rev. Genet.
2009,7, 333–340. [CrossRef]
80.
Lv, X.; Wang, L.; Mei, A.; Xu, Y.; Ruan, X.; Wang, W.; Shao, J.; Yang, D.; Dong, X. Recent Nanotechnologies to Overcome the
Bacterial Biofilm Matrix Barriers. Small 2022, 2206220. [CrossRef]
81.
Mah, T.-F.C.; O’Toole, G.A. Mechanisms of biofilm resistance to antimicrobial agents. Trends Microbiol.
2001
,9, 34–39. [CrossRef]
82.
Hu, Y.; Ruan, X.; Lv, X.; Xu, Y.; Wang, W.; Cai, Y.; Ding, M.; Dong, H.; Shao, J.; Yang, D.; et al. Biofilm microenvironment-responsive
nanoparticles for the treatment of bacterial infection. Nano Today 2022,46, 101602. [CrossRef]
83.
Huang, L.; Dai, T.; Xuan, Y.; Tegos, G.P.; Hamblin, M.R. Synergistic Combination of Chitosan Acetate with Nanoparticle Silver as
a Topical Antimicrobial: Efficacy against Bacterial Burn Infections. Antimicrob. Agents Chemother.
2011
,55, 3432–3438. [CrossRef]
84.
Huh, A.J.; Kwon, Y.J. “Nanoantibiotics”: A new paradigm for treating infectious diseases using nanomaterials in the antibiotics
resistant era. J. Control. Release 2011,156, 128–145. [CrossRef] [PubMed]
85.
Tran, N.; Tran, P. Nanomaterial-Based Treatments for Medical Device-Associated Infections. ChemPhysChem
2012
,13, 2481–2494.
[CrossRef]
86.
Makvandi, P.; Wang, C.Y.; Zare, E.N.; Borzacchiello, A.; Niu, L.N.; Tay, F.R. Metal-Based Nanomaterials in Biomedical Applications:
Antimicrobial Activity and Cytotoxicity Aspects. Adv. Funct. Mater. 2020,30, 1910021. [CrossRef]
87.
Eckhardt, S.; Brunetto, P.S.; Gagnon, J.; Priebe, M.; Giese, B.; Fromm, K.M. Nanobio Silver: Its Interactions with Peptides and
Bacteria, and Its Uses in Medicine. Chem. Rev. 2013,113, 4708–4754. [CrossRef] [PubMed]
88.
Yougbaré, S.; Chou, H.-L.; Yang, C.-H.; Krisnawati, D.I.; Jazidie, A.; Nuh, M.; Kuo, T.-R. Facet-dependent gold nanocrystals for
effective photothermal killing of bacteria. J. Hazard. Mater. 2021,407, 124617. [CrossRef] [PubMed]
89.
Lara, H.H.; Ayala-Núnez, N.V.; del Carmen Ixtepan Turrent, L.; Rodríguez Padilla, C. Bactericidal effect of silver nanoparticles
against multidrug-resistant bacteria. World J. Microbiol. Biotechnol. 2010,26, 615–621. [CrossRef]
90.
Knetsch, M.L.W.; Koole, L.H. New Strategies in the Development of Antimicrobial Coatings: The Example of Increasing Usage of
Silver and Silver Nanoparticles. Polymers 2011,3, 340–366. [CrossRef]
91.
Qu, X.; Alvarez, P.J.; Li, Q. Applications of nanotechnology in water and wastewater treatment. Water Res.
2013
,47, 3931–3946.
[CrossRef]
92.
Veerapandian, M.; Lim, S.K.; Nam, H.M.; Kuppannan, G.; Yun, K.S. Glucosamine-functionalized silver glyconanoparticles:
Characterization and antibacterial activity. Anal. Bioanal. Chem. 2010,398, 867–876. [CrossRef]
93.
Zare, B.; Faramarzi, M.A.; Sepehrizadeh, Z.; Shakibaie, M.; Rezaie, S.; Shahverdi, A.R. Biosynthesis and recovery of rod-shaped
tellurium nanoparticles and their bactericidal activities. Mater. Res. Bull. 2012,47, 3719–3725. [CrossRef]
94.
Webster, T.; Wang, Q.; Perez, J.M. Inhibited growth of Pseudomonas aeruginosa by dextran- and polyacrylic acid-coated ceria
nanoparticles. Int. J. Nanomed. 2013,8, 3395–3399. [CrossRef]
95.
Liu, Y.; He, L.; Mustapha, A.; Li, H.; Hu, Z.; Lin, M. Antibacterial activities of zinc oxide nanoparticles against Escherichia coli
O157:H7. J. Appl. Microbiol. 2009,107, 1193–1201. [CrossRef]
96.
Huang, Z.; Zheng, X.; Yan, D.; Yin, G.; Liao, X.; Kang, Y.; Yao, Y.; Huang, D.; Hao, B. Toxicological Effect of ZnO Nanoparticles
Based on Bacteria. Langmuir 2008,24, 4140–4144. [CrossRef]
97.
Kwak, S.-Y.; Kim, S.H.; Kim, S.S. Hybrid organic/inorganic reverse osmosis (RO) membrane for bactericidal anti-fouling. 1.
Preparation and characterization of TiO
2
nanoparticle self-assembled aromatic polyamide thin-film-composite (TFC) membrane.
Environ. Sci. Technol. 2001,35, 2388–2394. [CrossRef]

Nanomaterials 2023,13, 483 23 of 27
98.
Hernandez-Delgadillo, R.; Velasco-Arias, D.; Diaz, D.; Arevalo-Niño, K.; Garza-Enriquez, M.; De la Garza-Ramos, M.A.; Cabral-
Romero, C. Zerovalent bismuth nanoparticles inhibit Streptococcus mutans growth and formation of biofilm. Int. J. Nanomed.
2012
,
7, 2109–2113. [CrossRef]
99.
Karlsson, H.L.; Cronholm, P.; Gustafsson, J.; Möller, L. Copper Oxide Nanoparticles Are Highly Toxic: A Comparison between
Metal Oxide Nanoparticles and Carbon Nanotubes. Chem. Res. Toxicol. 2008,21, 1726–1732. [CrossRef]
100.
Lankveld, D.P.K.; Oomen, A.G.; Krystek, P.; Neigh, A.; De Jong, A.T.; Noorlander, C.W.; Van Eijkeren, J.; Geertsma, R.E.; De Jong,
W.H. The kinetics of the tissue distribution of silver nanoparticles of different sizes. Biomaterials 2010,31, 8350–8361. [CrossRef]
101.
Qiu, Z.; Yu, Y.; Chen, Z.; Jin, M.; Yang, D.; Zhao, Z.; Wang, J.; Shen, Z.; Wang, X.; Qian, D.; et al. Nanoalumina promotes the
horizontal transfer of multiresistance genes mediated by plasmids across genera. Proc. Natl. Acad. Sci. USA
2012
,109, 4944–4949.
[CrossRef]
102.
Veerapandian, M.; Yun, K. Functionalization of biomolecules on nanoparticles: Specialized for antibacterial applications. Appl.
Microbiol. Biotechnol. 2011,90, 1655–1667. [CrossRef]
103.
Kotagiri, N.; Lee, J.S.; Kim, J.-W. Selective pathogen targeting and macrophage evading carbon nanotubes through dextran sulfate
coating and PEGylation for photothermal theranostics. J. Biomed. Nanotechnol. 2013,9, 1008–1016. [CrossRef]
104.
Kang, S.; Pinault, M.; Pfefferle, L.D.; Elimelech, M. Single-Walled Carbon Nanotubes Exhibit Strong Antimicrobial Activity.
Langmuir 2007,23, 8670–8673. [CrossRef] [PubMed]
105.
Xia, X.R.; Monteiro-Riviere, N.A.; Riviere, J.E. Intrinsic biological property of colloidal fullerene nanoparticles (nC60): Lack of
lethality after high dose exposure to human epidermal and bacterial cells. Toxicol. Lett.
2010
,197, 128–134. [CrossRef] [PubMed]
106.
Rajesh, S.; Koshi, E.; Philip, K.; Mohan, A. Antimicrobial photodynamic therapy: An overview. J. Indian Soc. Periodontol.
2011
,15,
323–327. [CrossRef]
107.
Hancock, R.E.W.; Sahl, H.-G. Antimicrobial and host-defense peptides as new anti-infective therapeutic strategies. Nat. Biotechnol.
2006,24, 1551–1557. [CrossRef]
108.
Peschel, A.; Sahl, H.-G. The co-evolution of host cationic antimicrobial peptides and microbial resistance. Nat. Rev. Genet.
2006
,4,
529–536. [CrossRef] [PubMed]
109.
Eby, D.M.; Farrington, K.E.; Johnson, G.R. Synthesis of Bioinorganic Antimicrobial Peptide Nanoparticles with Potential
Therapeutic Properties. Biomacromolecules 2008,9, 2487–2494. [CrossRef]
110.
Blin, T.; Purohit, V.; Leprince, J.; Jouenne, T.; Glinel, K. Bactericidal Microparticles Decorated by an Antimicrobial Peptide for the
Easy Disinfection of Sensitive Aqueous Solutions. Biomacromolecules 2011,12, 1259–1264. [CrossRef]
111.
Liu, L.; Xu, K.; Wang, H.; Jeremy Tan, P.; Fan, W.; Venkatraman, S.S.; Li, L.; Yang, Y.-Y. Self-assembled cationic peptide
nanopar-ticles as an efficient antimicrobial agent. Nat. Nanotechnol. 2009,4, 457–463. [CrossRef]
112.
Makovitzki, A.; Baram, J.; Shai, Y. Antimicrobial lipopolypeptides composed of palmitoyl di- and tricationic peptides:
In vitro
and
in vivo
activities, self-assembly to nanostructures, and a plausible mode of action. Biochemistry
2008
,47, 10630–10636. [CrossRef]
113.
Khara, J.S.; Wang, Y.; Ke, X.-Y.; Liu, S.; Newton, S.M.; Langford, P.R.; Yang, Y.Y.; Ee, P.L.R. Anti-mycobacterial activities of
synthetic cationic α-helical peptides and their synergism with rifampicin. Biomaterials 2014,35, 2032–2038. [CrossRef]
114.
Engler, A.C.; Wiradharma, N.; Ong, Z.Y.; Coady, D.J.; Hedrick, J.L.; Y. -Yang, Y. Emerging trends in macromolecular antimi-crobials
to fight multi-drug-resistant infections. Nano Today 2012,7, 201–222. [CrossRef]
115.
Song, J.; Kang, H.; Lee, C.; Hwang, S.H.; Jang, J. Aqueous Synthesis of Silver Nanoparticle Embedded Cationic Polymer
Nanofibers and Their Antibacterial Activity. ACS Appl. Mater. Interfaces 2012,4, 460–465. [CrossRef]
116.
Kong, M.; Chen, X.G.; Xing, K.; Park, H.J. Antimicrobial properties of chitosan and mode of action: A state of the art review. Int. J.
Food Microbiol. 2010,144, 51–63. [CrossRef]
117.
Qi, L.; Xu, Z.; Jiang, X.; Hu, C.; Zou, X. Preparation and antibacterial activity of chitosan nanoparticles. Carbohydr. Res.
2004
,339,
2693–2700. [CrossRef]
118.
Rabea, E.I.; Badawy, M.E.-T.; Stevens, C.V.; Smagghe, G.; Steurbaut, W. Chitosan as Antimicrobial Agent: Applications and Mode
of Action. Biomacromolecules 2003,4, 1457–1465. [CrossRef]
119.
Friedman, A.J.; Phan, J.; Schairer, D.O.; Champer, J.; Qin, M.; Pirouz, A.; Blecher-Paz, K.; Oren, A.; Liu, P.T.; Modlin, R.L.
Antimi-crobial and anti-inflammatory activity of chitosan–alginate nanoparticles: A targeted therapy for cutaneous pathogens. J.
Investig. Dermatol. 2013,133, 1231–1239. [CrossRef]
120.
Potara, M.; Jakab, E.; Damert, A.; Popescu, O.; Canpean, V.; Astilean, S. Synergistic antibacterial activity of chitosan–silver
nanocomposites on Staphylococcus aureus.Nanotechnology 2011,22, 135101. [CrossRef]
121.
Hosseinkhani, H.; Hong, P.-D.; Yu, D.-S. Self-Assembled Proteins and Peptides for Regenerative Medicine. Chem. Rev.
2013
,113,
4837–4861. [CrossRef]
122.
Elsabahy, M.; Heo, G.S.; Lim, S.-M.; Sun, G.; Wooley, K.L. Polymeric Nanostructures for Imaging and Therapy. Chem. Rev.
2015
,
115, 10967–11011. [CrossRef]
123.
Jadidi, A.; Davoodian, F.; Salahinejad, E. Effect of poly lactic-co-glycolic acid encapsulation on drug delivery kinetics from
vancomycin-impregnated Ca-Mg silicate scaffolds. Prog. Org. Coat. 2020,149, 105970. [CrossRef]
124.
Jadidi, A.; Shokrgozar, M.A.; Sardari, S.; Maadani, A.M. Gefitinib-loaded polydopamine-coated hollow mesoporous silica
nanoparticle for gastric cancer application. Int. J. Pharm. 2022,629, 122342. [CrossRef] [PubMed]
125.
Kashkooli, F.M.; Soltani, M.; Momeni, M.M.; Rahmim, A. Enhanced Drug Delivery to Solid Tumors via Drug-Loaded Nanocarriers:
An Image-Based Computational Framework. Front. Oncol. 2021,11, 655781. [CrossRef]

Nanomaterials 2023,13, 483 24 of 27
126.
Kashkooli, F.M.; Rezaeian, M.; Soltani, M. Drug delivery through nanoparticles in solid tumors: A mechanistic understanding.
Nanomedicine 2022,17, 695–716. [CrossRef] [PubMed]
127.
Zhang, L.; Pornpattananangkul, D.; Hu, C.-M.; Huang, C.-M. Development of Nanoparticles for Antimicrobial Drug Delivery.
Curr. Med. Chem. 2010,17, 585–594. [CrossRef] [PubMed]
128. Poole, K. Mechanisms of bacterial biocide and antibiotic resistance. J. Appl. Microbiol. 2002,92, 55S–64S. [CrossRef]
129.
Goharshadi, E.K.; Goharshadi, K.; Moghayedi, M. The use of nanotechnology in the fight against viruses: A critical review.
Co-Ord. Chem. Rev. 2022,464, 214559. [CrossRef]
130.
De Siqueira, L.B.D.O.; Matos, A.P.D.S.; da Silva, M.R.M.; Pinto, S.R.; Santos-Oliveira, R.; Ricci-Júnior, E. Pharmaceutical
nanotechnology applied to phthalocyanines for the promotion of antimicrobial photodynamic therapy: A literature review.
Photodiagnosis Photodyn. Ther. 2022,39, 102896. [CrossRef]
131.
Nicolosi, D.; Scalia, M.; Nicolosi, V.M.; Pignatello, R. Encapsulation in fusogenic liposomes broadens the spectrum of action of
vancomycin against Gram-negative bacteria. Int. J. Antimicrob. Agents 2010,35, 553–558. [CrossRef]
132.
Cheow, W.S.; Chang, M.W.; Hadinoto, K. The roles of lipid in anti-biofilm efficacy of lipid–polymer hybrid nanoparticles
encapsulating antibiotics. Colloids Surf. A Physicochem. Eng. Asp. 2011,389, 158–165. [CrossRef]
133.
Sanderson, N.M.; Guo, B.; Jacob, A.E.; Handley, P.S.; Cunniffe, J.G.; Jones, M.N. The interaction of cationic liposomes with the
skin-associated bacterium Staphylococcus epidermidis: Effects of ionic strength and temperature. Biochim. Biophys. Acta Biomembr.
1996,1283, 207–214. [CrossRef]
134.
Abed, N.; Couvreur, P. Nanocarriers for antibiotics: A promising solution to treat intracellular bacterial infections. Int. J.
Antimicrob. Agents 2014,43, 485–496. [CrossRef] [PubMed]
135.
Clemens, D.L.; Lee, B.-Y.; Xue, M.; Thomas, C.R.; Meng, H.; Ferris, D.; Nel, A.E.; Zink, J.I.; Horwitz, M.A. Targeted Intracellular
Delivery of Antituberculosis Drugs to Mycobacterium tuberculosis-Infected Macrophages via Functionalized Mesoporous Silica
Nanoparticles. Antimicrob. Agents Chemother. 2012,56, 2535–2545. [CrossRef] [PubMed]
136.
Forier, K.; Raemdonck, K.; De Smedt, S.C.; Demeester, J.; Coenye, T.; Braeckmans, K. Lipid and polymer nanoparticles for drug
delivery to bacterial biofilms. J. Control. Release 2014,190, 607–623. [CrossRef] [PubMed]
137.
Pissuwan, D.; Cortie, C.H.; Valenzuela, S.M.; Cortie, M.B. Functionalised gold nanoparticles for controlling pathogenic bacteria.
Trends Biotechnol. 2010,28, 207–213. [CrossRef]
138.
Gu, H.; Ho, P.L.; Tong, E.; Wang, L.; Xu, B. Presenting Vancomycin on Nanoparticles to Enhance Antimicrobial Activities. Nano
Lett. 2003,3, 1261–1263. [CrossRef]
139.
Zhao, Y.; Tian, Y.; Cui, Y.; Liu, W.; Ma, W.; Jiang, X. Small Molecule-Capped Gold Nanoparticles as Potent Antibacterial Agents
That Target Gram-Negative Bacteria. J. Am. Chem. Soc. 2010,132, 12349–12356. [CrossRef]
140.
Schairer, D.O.; Chouake, J.S.; Nosanchuk, J.D.; Friedman, A.J. The potential of nitric oxide releasing therapies as antimicrobial
agents. Virulence 2012,3, 271–279. [CrossRef]
141.
Privett, B.J.; Broadnax, A.D.; Bauman, S.J.; Riccio, D.A.; Schoenfisch, M.H. Examination of bacterial resistance to exogenous nitric
oxide. Nitric Oxide 2012,26, 169–173. [CrossRef]
142.
Pinto, R.V.; Carvalho, S.; Antunes, F.; Pires, J.; Pinto, M.L. Emerging Nitric Oxide and Hydrogen Sulfide Releasing Carriers for
Skin Wound Healing Therapy. ChemMedChem 2021,17, e202100429. [CrossRef]
143.
Afshari, A.R.; Sanati, M.; Mollazadeh, H.; Kesharwani, P.; Johnston, T.P.; Sahebkar, A. Nanoparticle-based drug delivery systems
in cancer: A focus on inflammatory pathways. Semin. Cancer Biol. 2022,86, 860–872. [CrossRef]
144.
Hetrick, E.M.; Shin, J.H.; Stasko, N.A.; Johnson, C.B.; Wespe, D.A.; Holmuhamedov, E.; Schoenfisch, M.H. Bactericidal Efficacy of
Nitric Oxide-Releasing Silica Nanoparticles. ACS Nano 2008,2, 235–246. [CrossRef]
145.
Lu, Y.; Slomberg, D.L.; Schoenfisch, M.H. Nitric oxide-releasing chitosan oligosaccharides as antibacterial agents. Biomaterials
2014,35, 1716–1724. [CrossRef]
146.
Han, G.; Martinez, L.R.; Mihu, M.R.; Friedman, A.J.; Friedman, J.M.; Nosanchuk, J.D. Nitric Oxide Releasing Nanoparticles Are
Therapeutic for Staphylococcus aureus Abscesses in a Murine Model of Infection. PLoS ONE 2009,4, e7804. [CrossRef]
147.
Friedman, A.J.; Han, G.; Navati, M.S.; Chacko, M.; Gunther, L.; Alfieri, A.; Friedman, J.M. Sustained release nitric oxide releasing
nanoparticles: Characterization of a novel delivery platform based on nitrite containing hydrogel/glass composites. Nitric Oxide
2008,19, 12–20. [CrossRef]
148.
Martinez, L.R.; Han, G.; Chacko, M.; Mihu, M.R.; Jacobson, M.; Gialanella, P.; Friedman, A.J.; Nosanchuk, J.D.; Friedman, J.M.
Antimicrobial and Healing Efficacy of Sustained Release Nitric Oxide Nanoparticles Against Staphylococcus aureus Skin Infection.
J. Investig. Dermatol. 2009,129, 2463–2469. [CrossRef]
149.
Chow, J.W.; Victor, L.Y. Combination antibiotic therapy versus monotherapy for gram-negative bacteraemia: A commentary. Int.
J. Antimicrob. Agents 1999,11, 7–12. [CrossRef]
150.
Toti, U.S.; Guru, B.R.; Hali, M.; McPharlin, C.M.; Wykes, S.M.; Panyam, J.; Whittum-Hudson, J.A. Targeted delivery of antibiotics
to intracellular chlamydial infections using PLGA nanoparticles. Biomaterials 2011,32, 6606–6613. [CrossRef]
151.
Carmona, D.; Lalueza, P.; Balas, F.; Arruebo, M.; Santamaría, J. Mesoporous silica loaded with peracetic acid and silver nano-
particles as a dual-effect, highly efficient bactericidal agent. Microporous Mesoporous Mater. 2012,161, 84–90. [CrossRef]
152.
Hurdle, J.G.; O’Neill, A.J.; Chopra, I.; Lee, R.E. Targeting bacterial membrane function: An underexploited mechanism for treating
persistent infections. Nat. Rev. Microbiol. 2011,9, 62–75. [CrossRef]

Nanomaterials 2023,13, 483 25 of 27
153.
Chono, S.; Tanino, T.; Seki, T.; Morimoto, K. Efficient drug targeting to rat alveolar macrophages by pulmonary administration of
ciprofloxacin incorporated into mannosylated liposomes for treatment of respiratory intracellular parasitic infections. J. Control.
Release 2008,127, 50–58. [CrossRef]
154.
Soltani, M.; Souri, M.; Moradi Kashkooli, F. Effects of hypoxia and nanocarrier size on pH-responsive nano-delivery system to
solid tumors. Sci. Rep. 2021,11, 19350. [CrossRef] [PubMed]
155.
Radovic-Moreno, A.F.; Lu, T.K.; Puscasu, V.A.; Yoon, C.J.; Langer, R.; Farokhzad, O.C. Surface charge-switching polymeric
na-noparticles for bacterial cell wall-targeted delivery of antibiotics. ACS Nano 2012,6, 4279–4287. [CrossRef] [PubMed]
156.
Pornpattananangkul, D.; Olson, S.; Aryal, S.; Sartor, M.; Huang, C.-M.; Vecchio, K.; Zhang, L. Stimuli-Responsive Liposome
Fusion Mediated by Gold Nanoparticles. ACS Nano 2010,4, 1935–1942. [CrossRef]
157.
Gao, W.; Vecchio, D.; Li, J.; Zhu, J.; Zhang, Q.; Fu, V.; Li, J.; Thamphiwatana, S.; Lu, D.; Zhang, L. Hydrogel containing
nanoparti-cle-stabilized liposomes for topical antimicrobial delivery. Acs Nano 2014,8, 2900–2907. [CrossRef] [PubMed]
158.
Pornpattananangkul, D.; Zhang, L.; Olson, S.; Aryal, S.; Obonyo, M.; Vecchio, K.; Huang, C.-M.; Zhang, L. Bacterial Toxin-
Triggered Drug Release from Gold Nanoparticle-Stabilized Liposomes for the Treatment of Bacterial Infection. J. Am. Chem. Soc.
2011,133, 4132–4139. [CrossRef]
159.
Xiong, M.-H.; Bao, Y.; Yang, X.-Z.; Wang, Y.-C.; Sun, B.; Wang, J. Lipase-sensitive polymeric triple-layered nanogel for “on-demand”
drug delivery. J. Am. Chem. Soc. 2012,134, 4355–4362. [CrossRef]
160.
Xiong, M.-H.; Li, Y.-J.; Bao, Y.; Yang, X.-Z.; Hu, B.; Wang, J. Bacteria-Responsive Multifunctional Nanogel for Targeted Antibiotic
Delivery. Adv. Mater. 2012,24, 6175–6180. [CrossRef]
161.
Shi, B.; Leung, D.Y.; Taylor, P.A.; Li, H. MRSA colonization is associated with decreased skin commensal bacteria in atopic
dermatitis. J. Investig. Dermatol. 2018,138, 1668. [CrossRef]
162.
Lu, B.; Ye, H.; Shang, S.; Xiong, Q.; Yu, K.; Li, Q.; Xiao, Y.; Dai, F.; Lan, G. Novel wound dressing with chitosan gold nanoparticles
capped with a small molecule for effective treatment of multiantibiotic-resistant bacterial infections. Nanotechnology
2018
,29,
425603. [CrossRef]
163.
Liu, M.; He, D.; Yang, T.; Liu, W.; Mao, L.; Zhu, Y.; Wu, J.; Luo, G.; Deng, J. An efficient antimicrobial depot for infectious
site-targeted chemo-photothermal therapy. J. Nanobiotechnol. 2018,16, 23. [CrossRef]
164.
Alfatemi, S.H.; Rad, M.S.; Iriti, M. Antimicrobial synergic effect of allicin and silver nanoparticles on skin infection caused by
methicillin-resistant Staphylococcus aureus spp. Ann. Med. Heath Sci. Res. 2014,4, 863–868. [CrossRef]
165.
Ran, X.; Du, Y.; Wang, Z.; Wang, H.; Pu, F.; Ren, J.; Qu, X. Hyaluronic Acid-Templated Ag Nanoparticles/Graphene Oxide
Composites for Synergistic Therapy of Bacteria Infection. ACS Appl. Mater. Interfaces 2017,9, 19717–19724. [CrossRef]
166.
Ribeiro, K.L.; Frías, I.A.; Franco, O.L.; Dias, S.C.; Sousa-Junior, A.A.; Silva, O.N.; Bakuzis, A.F.; Oliveira, M.D.; Andrade, C.A.
Clavanin A-bioconjugated Fe3O4/Silane core-shell nanoparticles for thermal ablation of bacterial biofilms. Colloids Surf. B
Biointerfaces 2018,169, 72–81. [CrossRef]
167.
Francolini, I.; Giansanti, L.; Piozzi, A.; Altieri, B.; Mauceri, A.; Mancini, G. Glucosylated liposomes as drug delivery systems of
usnic acid to address bacterial infections. Colloids Surf. B Biointerfaces 2019,181, 632–638. [CrossRef]
168.
Szaciłowski, K.; Macyk, W.; Stochel, G. Synthesis, structure and photoelectrochemical properties of the TiO
2
–Prussian blue
nanocomposite. J. Mater. Chem. 2006,16, 4603–4611. [CrossRef]
169.
Mir, M.; Ahmed, N.; Permana, A.D.; Rodgers, A.M.; Donnelly, R.F.; Rehman, A.U. Enhancement in site-specific delivery of
car-vacrol against methicillin resistant Staphylococcus aureus induced skin infections using enzyme responsive nanoparticles: A
proof of concept study. Pharmaceutics 2019,11, 606. [CrossRef] [PubMed]
170.
Nostro, A.; Papalia, T. Antimicrobial Activity of Carvacrol: Current Progress and Future Prospectives. Recent Pat. Anti-Infect.
Drug Discov. 2012,7, 28–35. [CrossRef]
171.
Lange-Asschenfeldt, B.; Marenbach, D.; Lang, C.; Patzelt, A.; Ulrich, M.; Maltusch, A.; Terhorst, D.; Stockfleth, E.; Sterry, W.;
Lademann, J. Distribution of Bacteria in the Epidermal Layers and Hair Follicles of the Human Skin. Ski. Pharmacol. Physiol.
2011
,
24, 305–311. [CrossRef]
172.
Hsu, C.-Y.; Yang, S.-C.; Sung, C.T.; Weng, Y.-H.; Fang, J.-Y. Anti-MRSA malleable liposomes carrying chloramphenicol for
ameliorating hair follicle targeting. Int. J. Nanomed. 2017,12, 8227–8238. [CrossRef]
173.
Alalaiwe, A.; Wang, P.-W.; Lu, P.-L.; Chen, Y.-P.; Fang, J.-Y.; Yang, S.-C. Synergistic Anti-MRSA Activity of Cationic Nanostructured
Lipid Carriers in Combination with Oxacillin for Cutaneous Application. Front. Microbiol. 2018,9, 1493. [CrossRef]
174.
Yang, S.; Han, X.; Yang, Y.; Qiao, H.; Yu, Z.; Liu, Y.; Wang, J.; Tang, T. Bacteria-targeting nanoparticles with microenviron-ment-
responsive antibiotic release to eliminate intracellular Staphylococcus aureus and associated infection. ACS Appl. Mater. Interfaces
2018,10, 14299–14311. [CrossRef] [PubMed]
175.
Yang, S.-C.; Aljuffali, I.A.; Sung, C.T.; Lin, C.-F.; Fang, J.-Y. Antimicrobial activity of topically-applied soyaethyl morpholinium
ethosulfate micelles against Staphylococcus species. Nanomedicine 2016,11, 657–671. [CrossRef]
176.
Kang, X.-Q.; Shu, G.-F.; Jiang, S.-P.; Xu, X.-L.; Qi, J.; Jin, F.-Y.; Liu, D.; Xiao, Y.-H.; Lu, X.-Y.; Du, Y.-Z. Effective targeted therapy for
drug-resistant infection by ICAM-1 antibody-conjugated TPGS modified
β
-Ga
2
O
3
: Cr
3+
nanoparticles. Theranostics
2019
,9, 2739.
[CrossRef]
177.
Wang, X.-S.; Situ, J.-Q.; Ying, X.-Y.; Chen, H.; Pan, H.-F.; Jin, Y.; Du, Y.-Z.
β
-Ga
2
O
3
:Cr
3+
nanoparticle: A new platform with
near infrared photoluminescence for drug targeting delivery and bio-imaging simultaneously. Acta Biomater.
2015
,22, 164–172.
[CrossRef] [PubMed]

Nanomaterials 2023,13, 483 26 of 27
178.
Kłodzi ´nska, S.N.; Priemel, P.A.; Rades, T.; Mørck Nielsen, H. Inhalable antimicrobials for treatment of bacterial bio-film-associated
sinusitis in cystic fibrosis patients: Challenges and drug delivery approaches. Int. J. Mol. Sci. 2016,17, 1688. [CrossRef]
179.
Deacon, J.; Abdelghany, S.M.; Quinn, D.J.; Schmid, D.; Megaw, J.; Donnelly, R.F.; Jones, D.S.; Kissenpfennig, A.; Elborn, J.S.;
Gilmore, B.F.; et al. Antimicrobial efficacy of tobramycin polymeric nanoparticles for Pseudomonas aeruginosa infections in cystic
fibrosis: Formulation, characterisation and functionalisation with dornase alfa (DNase). J. Control. Release
2015
,198, 55–61.
[CrossRef]
180.
Casciaro, B.; D’Angelo, I.; Zhang, X.; Loffredo, M.R.; Conte, G.; Cappiello, F.; Quaglia, F.; Di, Y.-P.P.; Ungaro, F.; Mangoni, M.L.
Poly(lactide-co-glycolide) Nanoparticles for Prolonged Therapeutic Efficacy of Esculentin-1a-Derived Antimicrobial Peptides
against Pseudomonas aeruginosa Lung Infection: In Vitro and in Vivo Studies. Biomacromolecules 2019,20, 1876–1888. [CrossRef]
181.
Chen, M.; Xie, S.; Wei, J.; Song, X.; Ding, Z.; Li, X. Antibacterial micelles with vancomycin-mediated targeting and pH/lipase-
triggered release of antibiotics. ACS Appl. Mater. Interfaces 2018,10, 36814–36823. [CrossRef]
182.
Wang, Y.; Yuan, Q.; Feng, W.; Pu, W.; Ding, J.; Zhang, H.; Li, X.; Yang, B.; Dai, Q.; Cheng, L.; et al. Targeted delivery of antibiotics
to the infected pulmonary tissues using ROS-responsive nanoparticles. J. Nanobiotechnol. 2019,17, 1–16. [CrossRef]
183.
Hsu, C.-Y.; Sung, C.T.; Aljuffali, I.A.; Chen, C.-H.; Hu, K.-Y.; Fang, J.-Y. Intravenous anti-MRSA phosphatiosomes mediate
en-hanced affinity to pulmonary surfactants for effective treatment of infectious pneumonia. Nanomed. Nanotechnol. Biol. Med.
2018,14, 215–225. [CrossRef]
184.
Tenland, E.; Pochert, A.; Krishnan, N.; Umashankar Rao, K.; Kalsum, S.; Braun, K.; Glegola-Madejska, I.; Lerm, M.; Robertson,
B.D.; Lindén, M. Effective delivery of the anti-mycobacterial peptide NZX in mesoporous silica nanoparticles. PLoS ONE
2019
,14,
e0212858. [CrossRef] [PubMed]
185.
Hussain, S.; Joo, J.; Kang, J.; Kim, B.; Braun, G.B.; She, Z.-G.; Kim, D.; Mann, A.P.; Mölder, T.; Teesalu, T. Antibiotic-loaded
nano-particles targeted to the site of infection enhance antibacterial efficacy. Nat. Biomed. Eng. 2018,2, 95–103. [CrossRef]
186.
Zhao, G.; Chen, Y.; He, Y.; Chen, F.; Gong, Y.; Chen, S.; Xu, Y.; Su, Y.; Wang, C.; Wang, J. Succinylated casein-coated pep-
tide-mesoporous silica nanoparticles as an antibiotic against intestinal bacterial infection. Biomater. Sci.
2019
,7, 2440–2451.
[CrossRef]
187.
Calabrese, I.; Cavallaro, G.; Scialabba, C.; Licciardi, M.; Merli, M.; Sciascia, L.; Liveri, M.L.T. Montmorillonite nanodevices for the
colon metronidazole delivery. Int. J. Pharm. 2013,457, 224–236. [CrossRef]
188.
Ping, Y.; Hu, X.; Yao, Q.; Hu, Q.; Amini, S.; Miserez, A.; Tang, G. Engineering bioinspired bacteria-adhesive clay nanoparticles
with a membrane-disruptive property for the treatment of Helicobacter pylori infection. Nanoscale
2016
,8, 16486–16498. [CrossRef]
189.
Angsantikul, P.; Thamphiwatana, S.; Zhang, Q.; Spiekermann, K.; Zhuang, J.; Fang, R.H.; Gao, W.; Obonyo, M.; Zhang, L. Coating
Nanoparticles with Gastric Epithelial Cell Membrane for Targeted Antibiotic Delivery against Helicobacter pylori Infection. Adv.
Ther. 2018,1, 1800016. [CrossRef]
190.
Huttunen, R.; Aittoniemi, J. New concepts in the pathogenesis, diagnosis and treatment of bacteremia and sepsis. J. Infect.
2011
,
63, 407–419. [CrossRef]
191.
Rai, A.; Pinto, S.; Velho, T.R.; Ferreira, A.F.; Moita, C.; Trivedi, U.; Evangelista, M.; Comune, M.; Rumbaugh, K.P.; Simões, P.N.;
et al. One-step synthesis of high-density peptide-conjugated gold nanoparticles with antimicrobial efficacy in a systemic infection
model. Biomaterials 2016,85, 99–110. [CrossRef]
192.
Qadri, S.; Haik, Y.; Mensah-Brown, E.; Bashir, G.; Fernandez-Cabezudo, M.J.; Al-Ramadi, B.K. Metallic nanoparticles to eradicate
bacterial bone infection. Nanomed. Nanotechnol. Biol. Med. 2017,13, 2241–2250. [CrossRef]
193.
Prasai, D.; Tuberquia, J.C.; Harl, R.R.; Jennings, G.K.; Bolotin, K.I. Graphene: Corrosion-Inhibiting Coating. ACS Nano
2012
,6,
1102–1108. [CrossRef]
194.
Fang, C.-H.; Tsai, P.-I.; Huang, S.-W.; Sun, J.-S.; Chang, J.Z.-C.; Shen, H.-H.; Chen, S.-Y.; Lin, F.H.; Hsu, L.-T.; Chen, Y.-C. Magnetic
hyperthermia enhance the treatment efficacy of peri-implant osteomyelitis. BMC Infect. Dis.
2017
,17, 516. [CrossRef] [PubMed]
195.
Król, A.; Pomastowski, P.; Rafi ´nska, K.; Railean-Plugaru, V.; Buszewski, B. Zinc oxide nanoparticles: Synthesis, antiseptic activity
and toxicity mechanism. Adv. Colloid Interface Sci. 2017,249, 37–52. [CrossRef]
196.
Bai, X.; Li, L.; Liu, H.; Tan, L.; Liu, T.; Meng, X. Solvothermal Synthesis of ZnO Nanoparticles and Anti-Infection Application in
Vivo. ACS Appl. Mater. Interfaces 2015,7, 1308–1317. [CrossRef] [PubMed]
197.
Haworth, C.S.; Bilton, D.; Chalmers, J.D.; Davis, A.M.; Froehlich, J.; Gonda, I.; Thompson, B.; Wanner, A.; O’Donnell, A.E.
Inhaled liposomal ciprofloxacin in patients with non-cystic fibrosis bronchiectasis and chronic lung infection with Pseudomonas
aeruginosa (ORBIT-3 and ORBIT-4): Two phase 3, randomised controlled trials. Lancet Respir. Med.
2019
,7, 213–226. [CrossRef]
[PubMed]
198.
Eleraky, N.E.; Allam, A.; Hassan, S.B.; Omar, M.M. Nanomedicine Fight against Antibacterial Resistance: An Overview of the
Recent Pharmaceutical Innovations. Pharmaceutics 2020,12, 142. [CrossRef]
199.
ClinicalTrials.gov. Liposomal Amikacin for Inhalation (LAI) for Nontuberculous Mycobacteria. Available online: https://
clinicaltrials.gov/ct2/show/NCT01315236 (accessed on 4 November 2019).
200.
ClinicalTrials.gov. Study of Dose Escalation of Liposomal Amikacin for Inhalation (ARIKAYCE
™
)—Extension Phase. Available
online: https://www.clinicaltrials.gov/ct2/show/NCT03905642 (accessed on 18 November 2019).
201.
ClinicalTrials.gov. Liposomal Amikacin for Inhalation (LAI) in the Treatment of Mycobacterium Abscessus Lung Disease.
Available online: https://clinicaltrials.gov/ct2/show/NCT03038178 (accessed on 4 November 2019).

Nanomaterials 2023,13, 483 27 of 27
202.
ClinicalTrials.gov. Extension Study of Liposomal Amikacin for Inhalation in Cystic Fibrosis (CF) Patients with Chronic Pseu-
domonas Aeruginosa (Pa) Infection. Available online: https://clinicaltrials.gov/ct2/show/NCT01316276 (accessed on 12
November 2019).
203. Mullard, A. FDA approves antitoxin antibody. Nat. Rev. Drug Discov. 2016,15, 811–812. [CrossRef]
204.
Azeredo da Silveira, S.; Perez, A. Improving the fate of severely infected patients: The promise of anti-toxin treatments and
superiority trials. Expert Rev. Anti-Infect. Ther. 2017,15, 973–975. [CrossRef]
205.
Laterre, P.-F.; Colin, G.; Dequin, P.-F.; Dugernier, T.; Boulain, T.; da Silveira, S.A.; Lajaunias, F.; Perez, A.; François, B. CAL02,
a novel antitoxin liposomal agent, in severe pneumococcal pneumonia: A first-in-human, double-blind, placebo-controlled,
ran-domised trial. Lancet Infect. Dis. 2019,19, 620–630. [CrossRef]
206.
Molchanova, N.; Hansen, P.R.; Franzyk, H. Advances in Development of Antimicrobial Peptidomimetics as Potential Drugs.
Molecules 2017,22, 1430. [CrossRef]
207. Stevens, D.A. Overview of amphotericin B colloidal dispersion (Amphocil). J. Infect. 1994,28, 45–49. [CrossRef]
208.
Boswell, G.W.; Buell, D.; Bekersky, I. AmBisome (liposomal amphotericin B): A comparative review. J. Clin. Pharmacol.
1998
,38,
583–592. [CrossRef]
209.
Paterson, D.L.; David, K.; Mrsic, M.; Cetkovsky, P.; Weng, X.-H.; Sterba, J.; Krivan, G.; Boskovic, D.; Lu, M.; Zhu, L.-P. Pre-
medication practices and incidence of infusion-related reactions in patients receiving AMPHOTEC
®
: Data from the Patient
Registry of Amphotericin B Cholesteryl Sulfate Complex for Injection Clinical Tolerability (PRoACT) registry. J. Antimicrob.
Chemother. 2008,62, 1392–1400. [CrossRef]
210.
Jadhav, M.; Bamba, A.; Shinde, V.; Gogtay, N.; Kshirsagar, N.; Bichile, L.; Mathai, D.; Sharma, A.; Varma, S.; Digumarathi, R.
Liposomal amphotericin B (Fungisome TM) for the treatment of cryptococcal meningitis in HIV/AIDS patients in India: A
mul-ticentric, randomized controlled trial. J. Postgrad. Med. 2010,56, 71. [CrossRef]
211.
Bruinenberg, P.; Blanchard, J.D.; Cipolla, D.C.; Dayton, F.; Mudumba, S.; Gonda, I. Inhaled liposomal ciprofloxacin: Once a day
management of respiratory infections. In Respiratory Drug Delivery; Davis Healthcare International Publishing: Orlando, FL, USA,
2010; pp. 73–82.
212.
ClinicalTrials.gov. Phase 3 Study with Ciprofloxacin Dispersion for Inhalation in Non-CF Bronchiectasis (ORBIT-3). Available
online: https://clinicaltrials.gov/ct2/show/NCT01515007 (accessed on 21 November 2019).
213.
ClinicalTrials.gov. Study to Evaluate Efficacy of LAI When Added to Multi-drug Regimen Compared to Multi-drug Regimen
Alone (CONVERT). Available online: https://clinicaltrials.gov/ct2/show/NCT02344004 (accessed on 25 October 2019).
214.
ClinicalTrials.gov. Study of the Clinical Effectiveness of a Human Monoclonal Antibody to C. Difficile Toxin A and Toxin B in
Patients with Clostridium Difficile Associated Disease. Available online: https://clinicaltrials.gov/ct2/show/NCT00350298?
term=anti+toxin&draw=3&rank=13 (accessed on 16 November 2019).
215.
Crowther, G.S.; Baines, S.D.; Todhunter, S.L.; Freeman, J.; Chilton, C.H.; Wilcox, M.H. Evaluation of NVB302 versus vancomycin
activity in an
in vitro
human gut model of Clostridium difficile infection. J. Antimicrob. Chemother.
2013
,68, 168–176. [CrossRef]
216.
Van der Velden, W.J.; van Iersel, T.M.; Blijlevens, N.; Donnelly, J.P. Safety and tolerability of the antimicrobial peptide human
lactoferrin 1-11 (hLF1-11). BMC Med. 2009,7, 44. [CrossRef]
217.
Zhang, W.; Li, Y.; Qian, G.; Wang, Y.; Chen, H.; Li, Y.-Z.; Liu, F.; Shen, Y.; Du, L. Identification and characterization of the
an-ti-methicillin-resistant Staphylococcus aureus WAP-8294A2 biosynthetic gene cluster from Lysobacter enzymogenes OH11.
Antimicrob. Agents Chemother. 2011,55, 5581–5589. [CrossRef]
218.
Kaplan, C.W.; Sim, J.H.; Shah, K.R.; Kolesnikova-Kaplan, A.; Shi, W.; Eckert, R. Selective Membrane Disruption: Mode of Action
of C16G2, a Specifically Targeted Antimicrobial Peptide. Antimicrob. Agents Chemother. 2011,55, 3446–3452. [CrossRef]
219.
ClinicalTrials.gov. A Study of DPK-060 to Investigate Clinical Safety and Efficacy in Patients with Acute External Otitis. Available
online: https://clinicaltrials.gov/ct2/show/NCT01447017 (accessed on 10 December 2019).
220.
Nilsson, A.C.; Janson, H.; Wold, H.; Fugelli, A.; Andersson, K.; Håkangård, C.; Olsson, P.; Olsen, W.M. LTX-109 Is a Novel Agent
for Nasal Decolonization of Methicillin-Resistant and -Sensitive Staphylococcus aureus. Antimicrob. Agents Chemother.
2015
,59,
145–151. [CrossRef]
221.
Knight-Connoni, V.; Mascio, C.; Chesnel, L.; Silverman, J. Discovery and development of surotomycin for the treatment of
Clostridium difficile.J. Ind. Microbiol. Biotechnol. 2016,43, 195–204. [CrossRef]
222.
Stiefel, U.; Pultz, N.J.; Helfand, M.S.; Donskey, C.J. Efficacy of Oral Ramoplanin for Inhibition of Intestinal Colonization by
Vancomycin-Resistant Enterococci in Mice. Antimicrob. Agents Chemother. 2004,48, 2144–2148. [CrossRef]
Disclaimer/Publisher’s Note:
The statements, opinions and data contained in all publications are solely those of the individual
author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to
people or property resulting from any ideas, methods, instructions or products referred to in the content.